3. Don't be afraid to ask questions
Odds are your server didn't know anything about sushi when they started working in the industry, so don't feel embarrassed if you don't have a nuanced understanding of the difference between blue and yellowfin tuna, or don't have three semesters worth of Japanese language classes under your kimono.
4. Don't order everything at once
Rattling off a super-complex order of sashimi and nigiri might make you think you look like a pro, but it isn't how pros actually do it. Order a few things at once, and your honest reactions will help guide your server to make sure you're getting flavors that match your palate.
5. Don't ask for soy sauce and wasabi if they're not served
Most sushi chefs aren't too into the idea of you giving their carefully made creations a bath in a pool of soy sauce. It overwhelms the flavors, and chances are the chef already gave it a delicate brush of soy. Wasabi and ginger are used as palate cleansers, not entrees.