Step 1: Define what you want. Often we think we know what we want, but we can only define it by what we do not want. In the process of defining all the things we do not desire we end up shifting our energy and attention to manifest that rather than what we want. Where we place our attention is where the energy of manifestation goes to work. Clearly working at manifesting our dreams this way will not be productive.
You claim that "positive thoughts always resulting in positive things" is not the basis of the LOA. In part you are correct. The foundational basis in science, as I alluded to in the article was that thought stuff particles travel through ether (not air) and interact with formless stuff to create whatever it is that you are thinking about. This was how "the law" started.

How To Manifest What I Desire