Eat well and enjoy! Exercise hard.
Laugh a lot. It really does make life happier.
Nurture relationships.
Have good manners.
Treat yourself well.
Take risks.
Be honest.
Bake things for people.
Get enough sleep. It helps. (I never do this one).
Follow the Golden Rule.
Wear matching underwear. (No, not because of that!).
Don't give up on those who are suffering. Move on from people who won't help themselves.
Let yourself be a goofy dork sometimes. It's fun. (Currently my bro and I are making ridiculous videos to be shown at Christmas).
I guess that's about all I have for now.