I'll add my own to the many already good posts. 1. Change my diet. No sugar, low-carb and high-fat. Avoid fast-food and processed food. I eat a lot of vegetabl

I'll add my own to the many already good posts. 1. Change my diet. No sugar, low-carb and high-fat. Avoid fast-food and processed food. I eat a lot of vegetables. This change alone made me feel better and I got a lot more lean. 2. Extra D-vitamin. I found it helps my mood, motivation and general energy levels especially during the winter. 3. Moderate exercise. Martial arts and some strength training on the side. I bought a TRX and I try to go to the gym, but generally I exercise at home. I also walk to school. 4. Don't skip on sleep. Generally the best advice I could give is to eat well and do some exercise.