Get plenty of calcium.
Be kind to your knees. You'll miss them when they're gone.
Maybe you'll marry, maybe you won't.
Maybe you'll have children, maybe you won't.
Maybe you'll divorce at 40, maybe you'll dance the funky chicken on your 75th wedding anniversary.
Whatever you do, don't congratulate yourself too much, or berate yourself either.
Your choices are half chance. So are everybody else's.
Enjoy your body. Use it every way you can. Don't be afraid of it or of what other people think of it. It's the greatest instrument you'll ever own.
Dance, even if you have nowhere to do it but your living room.
Read the directions, even if you don't follow them.
Do not read beauty magazines. They will only make you feel ugly.
Get to know your parents. You never know when they'll be gone for good.
Be nice to your siblings. They're your best link to your past and the people most likely to stick with you in the future.
Understand that friends come and go, but with a precious few you should hold on.
Work hard to bridge the gaps in geography and lifestyle, because the older you get, the more you need the people who knew you when you were young.