For me, the most important thing is to stick to my daily schedule. Every single day of the week. Once I skip one or two meals, work long hours, or stay up late

For me, the most important thing is to stick to my daily schedule. Every single day of the week. Once I skip one or two meals, work long hours, or stay up late, my life starts spiraling out of control. So I live on a fixed schedule now, which includes three hours of exercise per day: * One hour of swimming at 7AM; this forces me to get out of bed on time, and makes me hungry for breakfast. * One hour of rowing at 5PM; this forces me to stop working, and makes me hungry for dinner. * One hour of running at 11PM; this forces me to stop whatever I am doing that evening, and gets me tired for bed. (In addition I have hundreds of small rules: never go shopping alone, the bed is only for sex and sleeping, dinner must take at least fifteen minutes to prepare, ...) It does take a lot of time and self discipline (and monitoring by others), but it sure helps me to keep my life under control.