BJ Fogg's Tiny Habits. Essentially:
1. Pick a trigger -- something you already will definitely do at the rate of the new habit.
2. Find a version of the habit that takes no cognitive load and can be done in less than a minute.
3. Celebrate every time you do it.
The template is: After I X, I will do Y. X must be sure, Y must be small. You must do it after.
http://www.youtube.com/watch?v=AdKUJxjn-R8
I also suggest putting in a system that makes it impossible to not do what you want. For the games/netflix one, just get rid of them. Don't depend on willpower -- make a system
http://www.entrepreneur.com/article/230333
For eating right -- journal everything you eat -- no need to track anything fancy except what it was and you will see results. The magic is that you don't eat things because you don't want to write it down. If you track one other thing, put a + or - next to it to indicate whether you think it was a good choice or not.