I know a lot of people are turned off by all the rules, but I think they're fine--who wants to listen to your phone conversation anyway? Do: Get there early--they open at noon and if you're not one of the top ten or 12 people on the list you will be waiting until someone leaves. Do: Order things you don't normally get. The fish is of amazing quality and the chef works magic. If you want to splurge just ask for the chef's selection--this can vary in price from $30 to more than $70 a person, but it is worth it and promises to be something a little different. Do: Follow the rules--as everyone notes they are posted all over the place.
Don't: Go there with a group--the space is tiny and if you have more than four people and aren't there a half hour before they open you may be waiting for awhile and I wouldn't be surprised if your group is broken up so that everyone can be seated.