Get in shape. Exercise and tone up your body. Find a workout that suits your schedule and makes you feel good. Get started with these steps:
Keep a positive body image. You don't have to look anorexic to be in shape. Looking fit is more attractive than being too skinny. Remember, the super-skinny celebrities that you see in magazines are mostly touched up via PhotoShop.
Eat well. Do little things, like integrating more fruits and vegetables into your diet. Eat all of the required amounts of fruit and/or vegetables for your age.
Make sure to make an effort to work out at least a little bit. Even doing yoga a few times a week will make a difference.
Hydrate. It gets old, but drink at least 8 glasses of water per day to keep you slim and to keep your skin really healthy.