Source: How to pump up your willpower
By Courtney Shea, Globe and Mail Sun, Mar. 18, 2012
Gotta be well rested to have will-power.
You can improve will-power by training. Start with small goals and work up just like building physical stamina.
Just practice paying attention to your behaviour when it deviates from your goal.
Don't be pessimistic when you fail. Failure is not disaster but narrow-minded pessimism is certain doom.
Hang out with people who want the same thing as you. It helps you pay attention to what you want.
Reference: Kelly McGonigal - The Willpower Instinct