Look at it like this. At whatever vibrational state of being you are right now. It is sum of habitual activities you have created over some time. When you try to manifest a thing out of that place, you are using various techniques to change your vibrational level to match the vibrational state of the desired thing. But sometimes, after manifesting whatever you wanted, you may fall back to the vibrational plane you were at the start.

Why? Because your habits create vibration of your day. All those little things you do and don't even think about add up and make your day what it is. If you want to manifest a different state of being and make it permanent, you must re-create your habits to match your desired vibrational plane.

First you have to become aware of all of your habits. When you got them all pin down, you can start to change them through will power. But notice that you only have this much of will power for a day. If you focus it on several habits at once, you'll make small progress and will most probably give up soon. Therefore, try to change only one thing at once and add another only when you feel your new approach in that thing has became habitual. Eventually, you can push one habit after another to a different reality, thus having them re-created to match your new vibrational state of being. Once they become AUTOMATIC (habits).. they will sustain your vibration.

In short -> Vibrational state of being A -> identify all your habits -> which create your vibration -> push them through one by one using WILL POWER -> to desired Vibrational state of being B. Once they start to "root" -> they will sustain your desired vibration -> and use of will power will be 0 when your new habits settled fully.

As always, there's much more to this, but I hope this basic info answers your question sufficiently for now.