It's fine to use a fork instead of chopsticks; to transfer food from a serving dish to your bowl with a spoon; to shovel rice into your mouth with a ladle. Just don't use your hands on the food. "People will think you are Mongolian," said my guide, as I pushed rice on to my chopsticks with a finger.
If you finish everything on your plate (or every last sip of tea), it's a sign that you want more and the host/waiter/waitress will top you up. If you want to be very cool, knock gently on the table with your knuckles to say thanks for the refill.
Never leave your chopsticks standing upright in food. It's a death omen.
Never leave your chopsticks pointing at anyone - it's considered very rude. For the same reason, always point the spout of a teapot away from people.
When drinking tea or eating noodles, slurp as loudly as you can (very hard for a polite English person). If you don't, it's a sign that you're not enjoying it.
Alcohol is not taboo; though tea will be served automatically, and in abundance, it's fine to order a beer or a glass of wine with your meal as well.