1. Reduce calories and sweets.
2. Try to eat as much low-fat food (chicken, fish and yougurt) as it is possible.
3. Give up smoking.
4. Don't go to bed late. Lack of sleep causes that our skin age faster.
5. Keep calm and try to avoid stress at home, school or work.
6. Don't eat between meals if you don't want to put on weight.
7. Keep fit and stay in shape. Try to do some excercises, go jogging or go to the gym. But remember don't be a fitness fanatic. You need to stay in shape, but also you shouldn't exaggerate. Just try to keep a balanced lifestyle.