If it's something you should never do with your chopsticks, the Japanese have a special word for it. Observe:

hiroibashi, 拾い箸 ("picking up chopsticks")

Never pass food from your chopsticks directly to another person's chopsticks.

kakibashi, 掻き箸 ("shoveling chopsticks")

Never hold a bowl close to your face and rapidly shovel rice into your mouth.

kawaribashi, 変わり箸 ("changing chopsticks")

Never put back food you've already taken.

komibashi, 込み箸 ("stuffing chopsticks")

Never use your chopsticks to stuff an already full mouth with even more food.

kuwaebashi, 銜え箸 ("holding-in-mouth chopsticks")

Never let chopsticks dangle from your mouth or close your mouth around the ends of chopsticks for longer than is absolutely necessary to eat.

mayoibashi, 迷い箸 ("indecisive chopsticks")

Never wave chopsticks around in the air above your food, as if wondering what to eat next.

namidabashi, 涙箸 ("crying chopsticks")

Never wave wet chopsticks around so they drip soup all over.

neburibashi, 舐り箸 ("licking chopsticks")

Never lick or suck food off the ends of your chopsticks.

saguribashi, 探り箸 ("searching chopsticks")

Never stir your chopsticks around in a dish, looking for a certain thing to eat.

sashibashi, 刺し箸 ("stabbing chopsticks")

Never stab food with your chopsticks, like you would with a fork.

seseribashi, せせり箸 ("picking chopsticks")

Never use your chopsticks to pick your teeth.

tatakibashi, 叩き箸 ("beating chopsticks")

Never beat your chopsticks on the side of your bowl to demand attention.

tontonbashi, トントン箸 ("ton-ton chopsticks")

Never make the tips of your chopsticks even by hitting them against the table or dishes, which makes a sound like "ton-ton." Instead make them even by sliding them with your fingers.

tsukitatebashi, 突き立て箸 ("piercing chopsticks")

Never stick your chopsticks upright in your rice.

utsuribashi, 移り箸 ("capricious chopsticks")

Never pick up one kind of food with your chopsticks only to change your mind and pick up another kind instead.

yokobashi, 横箸 ("adjacent chopsticks")

Never hold your chopsticks side by side and use them as a spoon.

yosebashi, 寄せ箸 ("drawing-near chopsticks")

Never pull a bowl or plate closer with your chopsticks.

watashibashi, 渡し箸 ("bridging chopsticks")

Never rest your chopsticks across your bowl like a bridge.