I came across this interesting article a while back about relationships that really just reiterates @Corys excellent answer. Hope you find it helpful.

Everyone is your mirror.This is the greatest of all relationships secrets and the only one you really need to understand to transform all your relationships. Here it is again - every single person in your life is your mirror. What this means is that others are simply reflecting parts of your own consciousness back to you, giving you an opportunity to really see yourself and ultimately to grow. The qualities you most admire in others are your own and the same goes for those qualities you dislike. To change anything in your relationships, be the change you want to see.

Mirror Mirror on the Wall:Learn to recognise yourself in other people. Everything and everyone is your mirror. It is only when you understand what it truly means to see yourself reflected back at you, that there is no room for blame, there is no room for judgement and there is no room to feel like a victim of another person's actions or words. There is only room for real love based on understanding and gratitude. Compromise comes easy, forgiveness is a given and growth is inevitable. While this truth applies to all of your relationships, from your family, to your friends and colleagues, and even to those you deem your "enemy", it is your relationship with your significant other that enables you to take the closest, most accurate look at who you are.

When Only the Face Seems to Change: It is certainly no secret that all your intimate relationships tend to be similar. Surely you have noticed how the fundamentals seem to remain the same while only the face changes. The repetition of the same problems, the same feelings and the same insecurities often leave you despondent and even reluctant to try again. You surrender yourself to the belief that relationships are difficult and require much compromise and that the only relationship secret out there is luck, timing or even Divine Will. You can't help but notice how what starts off with such hope often ends with no hope at all.

There is One Common Denominator: What you perhaps haven't noticed though, is that in all these repetitive relationships there has always only been one common denominator - YOU. Whoever the person is that you have next to you, no matter how many times you change him or her, the fundamentals of your relationship will remain unchanged (albeit to varying degrees) because they are simply mirroring you. It can be no other way. This realisation may frustrate you at first and you may even reject the truth that everyone is your mirror. However, you will quickly come to see it as great news because it means that you too can enjoy those loving relationships that previously seemed out of reach. To do so, the only person you need to influence is yourself.

What are You Really Seeing in the Mirror:To internalise this truth, that everyone is your mirror, you must first understand it. Your relationships with others are your opportunity to experience yourself and grow. They are a perfect mirror of your inner relationship with yourself and the beliefs you have acquired about life and love. Everything you admire in another person belongs to you and the same goes for all that which you dislike. In order for you to recognise a certain quality in another, then it must be part of your consciousness. You could not see it otherwise. Essentially, the bottom-line cause of break-ups and divorce, is when one or both of the partners can no longer stand to see themselves in the other person. To best understand how everyone is your mirror, think in terms of these three categories: your beliefs, your qualities, and your actions.

Your Beliefs are Staring You in the Face: Your beliefs about relationships, about men, about women, about love and life in general are all there for you to see in your relationships. We have all acquired certain beliefs throughout our lifetime that cause us to react and act in certain habitual ways that either support us or don't. This is most notable in our relationships because in order to experience anything or anyone you must first relate to it. For instance, if you believe that men or women are not to be trusted (no matter how trustworthy you are), or if you yourself have been willing to be the "other woman" or "other man" in the past, then by the Law of Attraction you will attract relationships in which a lack of trust is a major issue because that is where you have chosen to vibrate. Even if your partner is being faithful to you, you will look for reasons to prove otherwise and, as the saying goes, you always find what you are looking for.

Where Did Your Beliefs Come From? The problem is that you did not consciously choose many (if not any) of those beliefs that govern your experiences and relationships at the subconscious level. Instead, your beliefs were, unbeknown to you, handed to you by society, the media, your parents and your friends. There are also those beliefs that came part and parcel with your culture and upbringing, and the stricter your culture in the area of relationships, the more ingrained those specific beliefs. Since your relationships are based on those beliefs, your experiences only prove to re-enforce them for you, thereby creating something of a virtuous or vicious cycle depending on whether your beliefs support a healthy and balanced relationship or not.

Owning Up to Your Qualities: Every quality that you see in your partner, whether you admire it or not, is your mirror - it is showing you who you are. The more you dislike a certain quality, the more it is showing you a part of your consciousness that you are not acknowledging. For instance, if you dislike your partner's jealous nature, you will find that you too are jealous perhaps not of him or her but of others. If your partner's competitiveness annoys you, you will find that you too are competitive. If your partner's negativity or insecurities get you down, you will find that you too have a negative nature and the same insecurities. The only reason that these qualities are annoying you is because they are also yours. As long as you do not acknowledge them as your own they will continue to frustrate you, while owning up to them provides you with the chance to grow.

When Positive Qualities Annoy You: Interestingly, you may find that even some positive qualities annoy you. For example, if your partner's overly kind and giving nature frustrates you, it is showing you that you too want to become more kind and giving but are resisting doing so. Alternatively, your partners' ability to forgive may make you uneasy. Instead of becoming frustrated, see it as an opportunity to learn forgiveness. This ties into why opposites appear to attract as explained later in this article.

Your Actions - How Do You Treat Yourself and Others? When your partner acts in a particular way that upsets you, you will find that you too act in the same way, most likely not towards him or her but towards yourself and probably others. The more a particular action frustrates you, the more it reflects a part of you that you are not owning. If your partner treats you with disrespect, look within yourself and see who you treat with similar disrespect, whether it be a friend, a family member or yourself. If your partner criticises you, you will find that you are critical of yourself and most probably of others. If your partner ignores your needs, you will find that you too ignore your own needs or those of others. Ultimately, you teach others how to treat you by how you treat yourself.

Reconciling Opposites Attract with Like Attracts Like: You may have heard that opposites attract and indeed this often appears to be the case. So how can relationships always be your mirror if opposites attract? The answer lies in the Law of Polarity that states that "everything is dual, everything has poles; everything has its pair of opposites; opposites are identical in nature, but different in degree". In other words, qualities that appear to be opposites are in fact two extremes of the same quality. For instance hot and cold may appear to be opposite but are varying degrees of that which we call temperature. The same applies to all human qualities and emotions.

You may find that the quality you see in your partner appears to be the opposite of your own quality, but in fact it is the same quality expressed in a different way. It is still your mirror. For example, the introvert attracts the extrovert, the weak attracts the strong, the giving attracts the taking. Such seemingly opposite partners attract each other so that they can learn from each other and bring their own extreme quality into balance. In order to attract your opposite, you yourself have to be at the other end of the spectrum and so are unbalanced as far as that quality is concerned. Simply put, opposites attract in search of balance. When none of your qualities are at either extreme of the spectrum, then you can no longer attract its opposite.

Abusive Relationships are No Exception: This advice is aimed at healing and transforming your relationships. Emotionally and physically abusive relationships are no exception. Their reflection is no less accurate than that of any other relationship. At the root of abusive relationships you will usually find a severe lack of self-worth in the abused partner, which is re-iterated by their refusal to leave the abuser. The only way to rise above such relationships is through the power of self-love. In fact, it is the foundation of this great secret that everyone is your mirror.

To change your relationships you must understand that your relationships mirror you, your beliefs and your actions back to yourself. This is the key to transformation. We all have our so-called buttons which, when pushed, cause us to act or think in negative ways beyond our normal day-to-day selves. Get to know your buttons. Instead of becoming frustrated, know that your buttons are the keys to your growth. Instead of asking for them not to be pushed, examine the belief behind the trigger and resolve to change it. See your buttons as the red-alert alarms that bring to your attention those parts of your consciousness that are begging to be changed.

Self-Love as the Foundation: The truth that your relationships mirror your inner world re-enforces the greatest relationship advice you can ever receive, that of loving yourself. In a relationship in which your partner treats you with love and support, you will find that the basis for his or her love is the love you have towards yourself and so towards others. When you trust yourself and hence others, you will attract a trustworthy partner. When you believe in yourself and hence in others, you will attract a partner that believes in you. When you are kind to yourself and hence to others, you will attract a partner that is kind to you. When you love yourself and hence others, you will attract a loving partner and so on. Ultimately, a balanced and healthy love for oneself is the foundation of all successful relationships for it is truly the greatest love of all.

There is No Need to Blame Yourself: To change your relationship by recognising yourself in others, is not about blaming yourself or playing the victim. Instead, knowing that your relationships mirror you is about taking your own power back to create your reality and the relationships of your choice. It is about getting to know yourself and gaining new personal insights you never thought possible. In other words, it is about putting the ball back in your court to transform your relationships into the magic they are meant to be. It is your chance to grow. Do not fall into the trap of blaming yourself for everything that goes wrong. Rather, be grateful for the knowledge that you can change anything in your life without having to change anyone else; just yourself.

The Law of Gender: That our relationships mirror our inner world is underpinned by the Law of Gender. According to this Universal Law, everything and everyone contains both masculine and feminine elements. Know that despite your physical attributes, you are not your body. You have within yourself a feminine and a masculine you. The you that is beyond your body is both male and female. These two Principles within you have an ongoing relationship based on your beliefs. When you create a loving relationship between your masculine and your feminine selves it will be reflected back to you in your relationships with others in the physical world. This is what is meant by the advice to be the love you want to experience. When you stop searching for "the one", you will find that the one you have been looking for all along is yourself. You are the one.

Be the Change You Want to See:To change your relationships, you must change. Not others. This exercise is aimed at enabling you to see your relationships as a mirror. Make a list of all those things that you dislike in your partner and in your relationship. All those things you wish were different whether it be your partner's specific actions or qualities or things that are "wrong" with your relationship. Put your ego aside and do an honest audit of that list. Next to each unwanted action find examples of how you also act in that way, whether toward your partner, someone else or towards yourself. Next to all those unwanted qualities, write down examples of when you also display that quality, whether it is in your family environment, at your work, with your friends or with yourself. Next to all those things that are "wrong" with the relationship, write down your underlying belief about yourself, relationships or life that is being reflected by the specific unwanted part of your relationship.

In order to change your relationships, you must learn to see your relationships mirroring you. Be honest with yourself. There is no need to show your results to anyone else. This exercise is meant for you to learn about you. When you have completed your list and matched it up with your actions, qualities and beliefs, you are ready for change. Using meditation, creative visualization and repetitive affirmations you can shift your beliefs and habitual thoughts such that they empower rather than disempower your relationships. Once you see that the actions for which you criticise your partner are also your own, then resolve to change those negative actions on your part. Ultimately, learning to see all your relationships as a mirror enables you to transform and create relationships based on love rather than on fear and need.

What Will Happen Once You Change? Once you change so will your relationships mirror that change. You will find that as you begin to shift those habitual thoughts, beliefs and actions that your relationships will begin to transform before your very eyes. If you commit yourself to changing with persistence, you will find that the results you want to see are very quick to come. Your partner will become more loving and all those negative qualities which you once disliked will, as if by magic, start to disappear. This is the only way you can change your relationships short of pleading, bargaining or manipulating your partner, all of which have very short lived results and only serve to exacerbate the unwanted elements of your relationship.

Alternatively, you may also find that the role of your current partner finishes in your life causing him or her to leave effortlessly and amicably with relatively little or even no pain, thus making room for you to attract a new relationship into your life that mirrors your new-found beliefs, qualities and actions. The great spin-off is that you will see miraculous transformation not only in your relationship with your significant other but in all your relationships. You may even find that you no longer see your "enemies" as enemies but rather as your greatest teachers.

Self-Transformation is Real Magic: To see the behaviour of others transform in direct response to your transformation will astound you. This is real magic as at no time do you have to attempt to influence your partner to change, whether mentally, verbally or physically. This is what it really means to change your relationships. In fact, any attempt at changing someone else without first changing yourself will at best yield temporary results because the image being reflected back to you will not have changed. Remember, your relationships mirror you not your partner.

The Two-Fold Path to Change Your Relationships:There are only ever two paths to true change in life. The first path is pain, which is the most common. Many people have seen their relationships and lives change through much pain. As their experiences become more and more painful, to the point that they can no longer bear the suffering that is brought on by their own beliefs, they are forced to shift. The second path is knowledge. It is the path less travelled. When you learn a new truth and apply it in your life, you will effortlessly enjoy the changes you would otherwise only come to know through pain. The application of knowledge is the key that unlocks its power. Resolve to make knowledge the path you walk down on the road to changing your relationships into the loving experience it is meant to be.

Endeavour to learn the lesson before you change the teacher.

In a nutshell, to change your relationship you must learn to see all your relationships as your mirror, reflecting parts of your Consciousness back to you. When you learn to recognise all those qualities that you both like and dislike in your partner as your own, you will have learnt the great secret that the only path to change is through yourself. You will no longer have to hope or wish that your partner changes or be frustrated with his or her actions or constantly feel that you are compromising yourself to keep a relationship alive. Once you change yourself and your beliefs, you will find your relationships transforming in ways you never dreamt possible. Ultimately, when you find true love within yourself you will create and attract it effortlessly in your outer world.

Taken from http://www.mind-your-reality.com/your_mirror.html#Part_2

I personally like the idea that LOA and manifestation isn't actually influencing others as such, but that it is instead influencing different infinite versions of other people to show up in certain situations in response to your own manifestations. I also like the idea that when you use Law of Attraction in a positive way (similarly to in a negative way) you are branching off into a different Universe to a different version of yourself that is in the more positive situation that you have manifested.

So, in manifesting the ideal situation for yourself there is absolutely no need to worry about impacting your manifestations on others. Everyone else in the world is doing exactly the same thing, using positive and negative LOA, whether they know it or not. In the same way that you may 'manifest' someone into appearing into your life, someone else in another parallel Universe may influence you to positively show up in their life, even though the current self that you are inhabiting will never know it.

Do not try that! Weak souls (in the sense of having a craving for something, unfulfilled desires) may attract other souls who are looking for a body as to fulfill their unfulfilled desires. Conversely, you may master some souls only if they are weak in the above sense. But be careful! The forces which interact to produce the phenomena of any action: souls, matter and the Supreme Soul (God), are threaded by the law of karma. Thus you will be creating a karmic account for you. It means you will have to pay in the same coin--someone more powerful will master you! Do you feel that it is worth it? Karmic result is sure to ensue! When you act, there are more than 99% factors outside you to make your action possible, and your part is too insignificant as to claim doership to your action. The same factors will see that every action have its consequence! tdjaum "AT" gmail.com

Additional: Don’t worry, you can take the principle behind it—forget the details. I will come to your point. There is one person very explosive in the office where my wife works. Nobody escapes his wrath and shouting! My wife asked me how to work around him. I told her to really feel GOOD about him in her heart, look at his very essence—the image of God within him that lies dormant temporarily rather than the externals that irritates others. Send REALLY good wishes to him always, especially before going to him for some work-related matter. She says this works perfectly, she has never experienced even slightly negative treatment from this person. This may be interpreted as influencing the other person. But it is not. What actually happens is that when you send good wishes, you are a donor, positive, stronger, proves like a rock mountain against which the weak flies can exert no force.

The only differences between influence & control are intention & success rate. And there are times when either can be appropriate, and times when either can be worthy of the warnings given by T D.

@lex: "So I figure someone who has achieved that level of enlightenment has more power (greater influence) over those that are not[...]"

As a general rule there is correlation between influence and 'enlightenment', but it's easily possible for the 'unenlightened' or the enlightened of a nefarious variety to still exhibit this great degree of influence and/or control over others, without having the wisdom and tact to know when exercising their abilities can be detrimental to others. Also as one becomes more aware and in tune to the needs of others I'd say it actually becomes MORE likely they would choose to NOT exercise their ability despite becoming more capable at influencing others, because with this awareness you begin to see a deeper picture than "I should just make everyone behave in the way which I think makes the most sense while I'm around, rather than knowing when to let people walk their own paths."

At its most basic your question is akin to asking can the difference between someone showing up to meet you with a smile or frown can be influenced (or if successful, determined) by your actions, be they entirely mental or aided with behavior and approach as well.

Even in the best intentions such as above I think this can still have unforeseen consequences if not approached with balance, like anything else. Sure, everyone wants to be able to make others happy, or help guide them to what we believe are the most valuable decisions and encounters in life, and to a degree this is good. However taken to extremes I think it can be a problem, for example never allowing someone to simply experience something they may need to spend the time going through such as being upset and getting out their pent up emotions.

To me this is the difference between trying to cheer someone up because you know they're feeling down, but no longer pressing the matter once you see they're going through something critical to their growth and development as a person. Versus the other option of continuing this approach to such an extreme you no longer allow your friend to express themselves or come to you when they're hurt in a time of need, because even though you think you're doing them a favor by never letting them stay unhappy around you you're actually depriving them of comforting, a support system, and an unfortunate but sometimes necessary experience.

Some times you have to just let someone be themselves and do what comes naturally to them, even if you know inside there are a dozen different ways your actions could elevate or exacerbate their situation.

I tried my best to keep this answer as short as possible, but as usual, the answer had its own ideas.

Paradoxically, the answer you are looking for is actually hidden in the way you have phrased the question in the two ideas "influence someone" and "what is in your best interest".

WE ALREADY DO THIS, ALL THE TIME, IN A COMPLETELY UN-CONSCIOUS WAY.

The best way to wake up one's self to this truth is to observe the negative spectrum of reality, because most "spiritual" seekers tend to be in complete denial of their own participation in consciousness. (This is the nonphysical counterpart of reality).

Consider the following situations:

The State of Indifference:
YOUR MIND:
You are a blank slate and you are not projecting anything.
ANALYSIS:
You are not creating any opportunities "channels" for others to act upon and nothing happens to you.

Situation 1)
YOUR MIND:
I hate people who cut in front of me at the grocery checkout, why do people behave this way?
THE RESULT:
You project channels of opportunity so that the experience "why do people behave this way (cutting in line)" is energetically projected in every direction from where you stand, causing the physical experience of being treated this way by others to be available to anyone that is around you (to cut in front of you).
ANALYSIS:
You are allowing (manipulating) the free will of others to be expressed towards you in the form of cutting in front of you (if they choose to do so)

Situation 2)
YOUR MIND:
I am genuinely nice to everyone, I don't understand why people still try to take advantage of me (I feel taken advantage of and un-appreciated)
THE RESULT:
You project channels of opportunity where, when people interact with you, they have the choice and opportunity to take advantage of you in such a way that you will experience it as being taken advantage of in an un-appreciative way.
ANALYSIS:
You are allowing (manipulating) others to take advantage of you (if they choose to do so).

Situation 3)
YOUR MIND:
I am a victim.
THE RESULT:
You project an open invitation to all the different ways in which the experience of "I AM A VICTIM" can be expressed physically through you in a manner that is in "YOUR BEST INTEREST".
ANALYSIS:
Even though people who have the ability to express the Un-limited potential surround you, you will filter their un-limited potential within the narrow confines of YOUR BEST INTEREST of experiencing the position of "I AM A VICTIM".

So now, let's stack up the layers.

I am ready to make a change but, in spite of me being nice, I find that I am un-appreciated, taken advantage of regularly, making me feel like a constant victim.

It is not me... it's "THEM".

They are the ones treating me this way, and preventing me from making a change.

"I AM STUCK HERE"

So what is really happening here?

If you understand the three situations, you will know that others can only do to us what we allow to be done to us in the first place.

Let us look at that again.

OTHERS CAN ONLY ACT UPON WHAT WE ALLOW TO BE DONE TO US.

They can only act upon what we believe... This creates an energetic projection of potential reality ...that then attracts a similar vibration of participation by others.

IMAGINING = ALLOWING

Only what you imagine happening to you can be done to you by others.

So, in a way, you manipulate other's free will to align with what you imagine will happen to you next.

When you are approaching the bank machine, if you worry that someone might rob you or imagine yourself being robbed, in that moment, you allow anybody in the vicinity who has the desire to rob someone to align with your desire to be robbed.

You do not recognize this as a desire, but in the purest sense of manifestation, IT IS the desire to experience the fear that comes from being robbed.

Just like the constant attention to the idea, "I AM A VICTIM" is actually the physical desire to experience being the victim.

Therefore, we are constantly manipulating the free will of others to be expressed within the narrow confines of what we imagine others are doing to us.

Although, I started this answer by saying we do it in an unconscious way, the truth is it is very conscious, but we are in constant denial of it.

If you want to see how you are manipulating other's behaviour towards you, examine all the things you are worrying about, (what you worry that they might do to you).

Once you understand where your attraction exists, you can take command of it.

However, that is the paradox, you already command it...in the manner in which you do not want.