I've found that sort of self-awareness is incredibly helpful. My newest trick has been asking WHY I'm violating my previous plans - for instance, if I plan to diet, and end up over-eating, I'll ask myself, in the moment, why I'm doing this. It helps me form better plans in the future, as I can better predict my own future reasoning. For instance, I might over-eat because I got lost in work for eight hours and then realized I was utterly ravenous, or I might realize that I enjoy the pleasure of food more than I enjoy the idea of losing weight and drop the idea entirely :)