I'm going to do a top ten.
1. Read labels and become familiar with proper portion sizes
2. Always look up the calories when eating out, and when in doubt eat only half the plate
3. Avoid most overly-processed foods, especially those with added sugar
4. Don't let peers intimidate you into poor choices; you don't have to eat x just because so-and-so is
5. Hunger is not an emergency
6. Being satisfied does not mean being stuffed
7. Quality over quantity
8. Dessert is not a requirement to finish every meal
9. Fresh fruits and veggies aren't bland!
And most importantly . . .
10. Frosting should never be eaten with a spoon.