Here are a few thoughts on Willpower: Rediscovering the Greatest Human Strength by Roy F. Baumeister and John Tierney. (You can find reviews here, here and here.)
They talk a lot about the physical inputs of willpower. Being hungry can affect your decisions and self-control.
Roy F. Baumeister came up with the discovery that willpower is like a muscle: You can deplete it throughout the day.
There is not a lot of advice, until the last chapter.
They say you should make gradual changes, and to try to change one thing at a time. Trying to stop smoking while also trying to start exercising at the same time will be less successful than trying one or the other one at a time.
I will try to summarize some of the advice they give to increase willpower and self-control at the end of the book.
Since your supply of willpower is limited, you should
When your willpower becomes depleted, you will become more frustrated, and impulses will be harder to resist.
Make small changes over time instead of big changes right away.
Make a to-do list. It can relieve you from worrying about those decisions. But be aware that things make take longer than you plan.
You will be better off if you keep your life in order. If you expend less energy thinking about food, sleep, etc, you have more energy to do what you really want. I think I read that Einstein never changed the type of music he listened to, or the type of food he ate, so he could expend more energy for physics.
Look at the Nothing Alternative. An author profiled in the book would set time for writing. He did not have to write, but if he did not he could not do anything else productive.
They recommend monitoring your progress toward your goals. They also talk about the power of community to keep you on track to meet your goals.
A lot of the reviews were not too positive. I was not able to summarize it as well as I hoped to. I have to get it back to the library. It’s overdue. I reserved it a while back, and it came in right before I went to Austin. So I was not able to get to it (and a couple of other books) for about a week.
Update 2012-08-31_18.07.55: There was an article about this book on Business Insider on September 18, 2011.