When you share a plate, use the reverse side of chopsticks to avoid double dipping.
Do not bite into a piece of food and place it back to a plate. You cut food on a plate using chopsitcks, pick it up using chopsticks and eat all at once.
Use chopsticks holder to rest your chopstick directly in front of you and parallel to you, and holding side on a right.
Do not make wasabi soup with your soy sauce. Wasabi paralyzes your palette.
Do not dip sushi rice-side-down into the soy sauce, and let the sauce soak up into the rice. The soy sauce is not to flavor the rice but the fish. Dip the sushi rice-side up in the soy sauce and carry to the mouth.
Do not wave chopsticks to call somebody. Chopstick is for foods.