I really like going through this document and filling out answers for each of the questions in the "strategies" boxes.
"In my clinical work and my own behavior change efforts, I have noticed that one of the primary influences for successful behavior change is the way setbacks and lapses are managed. ... It is common during these moments to be self-critical and perceive that we are not competent enough or we do not have enough willpower to achieve our goal. ... When a setback occurs, I find it valuable to acknowledge the lapse as part of the change process and treat the occasion as a learning opportunity within a grand experiment. This mindset promotes flexibility, self-compassion and curiosity, which in turn facilitates problem-solving and faster return to the action stage."