Here is the most effective way. First of all, go onto google, print off all the images of your goals completed such as a 'six pack' 'mansion' and 'own business' etc. print them, stick them somewhere you will see them often. I put mine in a notebook alongside inspirational messages. Look at the images often, the subconscious will take note BUT will not yet be impressed with the information.
This may sound ridiculous, especially for anyone who's been hurt by rejection. But think of it more as a change in mindset. "Rejection is just the universe’s way of protecting you from someone who is not a right fit, so that you have room for someone who is," Thomas says. Besides, when you no longer fear rejection, you're more likely to go after what you really want.

I worked with a professional footballer once. He was getting very nervous about shooting goals. He kept missing even though he was very talented. I insisted that he kept watching himself on TV scoring goals and burned that image into his consciousness. I didn’t want him thinking about anything else. Every time he had a negative thought he was to switch that picture, either on the TV or on the TV in his mind. And he was to surround the thought with positive emotions of love and respect for himself.
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