Eat Modestly
Practicing good table manners is a good idea no matter where you're visiting, but there are some specific rules for China. Make sure you take small bites to avoid looking gluttonous. You should also avoid stretching your neck over your food, opening your mouth wide to take a bite, and sticking out your tongue to catch the food.
Spitting
Most people find spitting gross, but China doesn't think so. Professor Ross Coomber told BBC News, "In China, many people view spitting as a cleansing action for the body. It should be acknowledged that many Asian cultures see the act of putting used tissues into your pocket as disgusting and much worse than spitting." There you have it!