Set it and forget it. "When your willpower is depleted, you are even more likely to make decisions based on the environment around you. After all, if you're feeling drained, stressed, or overwhelmed then you're not going to go through a lot of effort to cook a healthy dinner or fit in a workout. You'll grab whatever is easiest. And that means that if you take just a little bit of time today to organize your room, your office, your kitchen, and other areas, then that adjustment in choice architecture can guide you toward better choices even when your willpower is fading."
Do You Suffer From Decision Fatigue? "The very act of making decisions depletes our ability to make them well. So how do we navigate a world of endless choice?"
In the late 1960s, Walter Mischel conducted a series of experiments on delayed gratification in preschoolers that became known as the Marshmallow Test. A recent New Yorker article talks about the eventual path that his research took and its wider implications. New research points to specific differences in brain activity between people with good self control and people with poor self control. Promising scientific findings aside, it's the (adorable) movie re-enactment of the marshmallow tests that is making news recently.
Stickk.com allows people to undertake commitment bonds: promises that they will do something (lose weight, quit smoking, etc.) or else forfeit a pre-determined amount of money to a charity. Either the honor system or a referee can be used to decide if the goal is met. The idea is related to Nobel prize-winner Thomas Schelling's concept of strategic precommitment. More here, here, and here.