Ask the chef for recommendations, which shows that you trust him.
Start your meal with a few slices of sashimi.
Start with a white fish, then move onto silver, work your way to red, and then onto fish with a heavier flavour such as salmon. This avoids the heavier fish flavours from overpowering the lighter ones.
You may use both chopsticks or fingers, but do remember to wipe your fingers with a wet towel before you start.
Do not pass food from your chopsticks to another person's chopsticks.
Use the back ends of the chopsticks to pick up sushi from a shared plate.
Do not hover your chopsticks above food while deciding on what to eat.
Do not pick up food using the chopsticks by stabbing through the food.
Do not lick, suck or chew on the chopsticks.
Do not use the chopsticks to drag something towards you.
It's considered rude to rub your chopsticks together to remove splinters. A good sushi bar will not provide low quality chopsticks.
Try to eat sushi in one mouthful. It's considered impolite to place an eaten sushi back on your plate.
If you are unable to do so, you may bite it but continue to hold the other half with your chopsticks and never put it back onto your plate.
Do not disassemble the sushi. Preserve the beauty of sushi.
Dip the topping, not the rice. Dip only a small corner and not submerge the sushi into the soy sauce as it will cause it to fall apart.
Also, the rice is seasoned and flavoured with the chef's expertise. You basically diss the chef if you dip the rice into soy sauce.
Do not mix the wasabi together with the soy sauce. Wasabi is to be added directly to the sushi.
Do not consume the ginger together with your sushi.
The pick pickled ginger is supposed to serve as a palate cleanser and should be eaten a slice at a time in between different flavours of sushi.
Ordering a simple sushi such as tuna maki is a sign that you are ending your order.
MOVING ON TO TYPES OF SUSHI...
Nigiri Sushi clump of rice with a slice of fish (raw) on it, but there are many variations now and cooked food such as crabstick or omelette usually have a strip of nori placed across it.
Gunkan Sushi clump of rice with a strip of nori wrapped around the perimeter of the rice, topped with diced ingredients such as chuka idako (seasoned octopus), or roe.
Inari Sushi clump of rice stuffed in inariage (seasoned beancurd pouch).
Makimono Sushi rice spread on nori with strips of ingredients. Sushi is rolled up tightly (like a swiss roll) and cut into slices.
Temaki Sushi quite similar to makimono but rice is spread on a smaller sheet of nori. Sushi is then rolled into a cone instead of cutting into slices.