Not only is it not wrong to ask for petty, unimportant things (as you put it) but, indeed, I highly encourage it!

When you throw a ball up in the air and watch it come down again, you don't feel bad that you tested The Law of Gravity, do you? The Law of Attraction is a similar impersonal natural phenomenon.

And, like the Law of Gravity, the Law of Attraction operates all the time in your life anyway whether you are aware of it or not. So you could say that you are testing it all the time anyway, albeit often not consciously.

Testing the Law with many minor requests is an excellent way to practice and gradually develop an intuitive feeling for when you are in alignment with what you want and when you are not.

You'll know how you are doing by whether the thing you want physically manifests or not.

And when something doesn't manifest, you can think about what you are doing differently with that thing as compared to the things that do manifest.

Once you start to recognize and habitualize this feeling of alignment, you'll be able to rely less on conscious processes and more on just going with the flow...things you want will seem to appear effortlessly into your life anyway at the right time regardless of whether you consciously ask for them or not.

But the key is practice....practice, practice, practice!

You wouldn't expect to start learning a foreign language today and tomorrow be speaking like a native of that country. You need practice.

And it's exactly the same with deliberate and precise manifesting...the more you practice, the more you'll start to see the clear correlation between your vibrational offering of thought and the Universe's response to it.

If I understand the "Message in a box" technique correctly, all that is required is for the desire to be launched (i.e. putting the message into the box), and then forgetting about it. So theoretically, no belief is required, since part of the technique is forgetting about it until you notice it show up in your experience.

The larger philosophical problem is that the Law of Attraction is essentially untestable since, if the manifestation does not occur, the devout will tell you that you simply lacked the necessary desire and belief, and that is why your manifestation didn't occur.

In other words, you're testing your faith, not the process itself.

This is less mystical than it sounds. People who practice any discipline have knowledge about that discipline that emerges from long practice with the tools of their trade. Whether you are a tennis player or a concert pianist, you started out with no knowledge at all. In the beginning, you had to have some faith that you were even capable of accomplishing it, but over time, that skill has become second nature to you.

So it is with manifestation. Those who practice it regularly, and understand how it works on an intuitive level, are able to perform better (i.e. manifest things consistently) than those who don't.

Some people will argue that the discipline, training and practice are not required, that you can simply "channel" the knowledge of a concert pianist. That's fine, but most people would like to call the skill their own, and be able to call on that skill at will in this physical platform we call life. In other words, they want it to be "real" and not "imaginary." And concert pianists and tennis players are doing more than just putting a message into a box.

Which is not to say that imagination, desire and belief are not important ingredients; they are. In fact, they are essential; you can't do anything without these ingredients. You must first believe you can do it, and have the desire to accomplish it, before you can manifest it.