Sit up straight. Speak politely. Chew your food well. Always take a sweater with you. Treat other people as you would like to be treated. So, any of this sound familiar? It's your mom's advice, and, yep, she's right. While it might be tempting to roll your eyes, the stars are giving you pretty much the same practical advice. And on that note, here's more: don't make that face, or it'll freeze that way!