1. Try everything. If your aunt Dianne makes her "new sweet potato casserole" that she is so obsessed with, try it, even if you don't like sweet potatoes. It will brighten the cook's day!
2. Do the dishes. The younger members of the family always help with the dishes. It's really sweet and appropriate to to offer to help out, your grandparents will be impressed!
3. Engage in conversations. I know you're so sick of being asked what you want to major in or if you have a boyfriend, but it's the way your family shows interest in your life. It's time to suck it up.
4. Talk to those who you don't see. I know you never see great aunt Beth, and you might care to socialize with your cousins, but go out of your way a few times to chat it up with her. She will appreciate more than you know.
5. Express thanks. To everyone. The hosts, your parents, cousins, aunts, uncles, grandparents! That's the meaning of the holiday!!