The positive feeling is the key to manifestation
Some techniques for positive thinking include visualization and affirmations, as practical application of the law of attraction.
When using any of these techniques you should also add a key ingredient:
The positive feeling
From my personal experience it is the good feeling, the positive emotion, what makes positive thinking work.
Basically, when you feel good the energy in you vibrates at a certain frequency, and attracts those physical manifestations that vibrate at the same frequency (find out more about how this works through quantum physics and the law of attraction).
Simply put, when you feel good with yourself, who you are and what you do, and you truly feel grateful for what you have, you are likely to bring more of these pleasant things, feelings, people and experiences into your life.
This is the nicest part.
When you do positive thinking affirmations imagine what it would feel like to do, be or have what you are affirming. "I'm perfectly healthy", "I'm open to abundance", "I'm a kind and loving person".
Play the game of pretending. Pretend you are already completely healthy and financially free. This game brings about positive emotions.
Remember that there is nothing wrong about pretending. You don't have to tell anybody - it's just like a game you play - one that makes you feel good.
You can also enhance your visualizations by adding positive emotions. See yourself landing the job you want, being great at what you like doing, or whatever it may be; and feel good as if all that was a reality already.
Feel grateful always for what you receive, good and bad experiences in your life, for gratefulness brings positive feelings to your life.
"Forget mistakes. Forget failure. Forget everything except what you're going to do now and do it. Today is your lucky day."
Will Durant