Soy sauce is an essential accompaniment to Sushi. Typically it is served
on the table either straight from the bottle, or from a little 'tea-pot' like
dispenser. You would place about a tablespoon of soy into a small dipping bowl,
then mix in a little wasabi to taste, then dip your sushi pieces into the sauce.
Some sushi chefs may find it offensive if you dip certain types of sushi into
the soy. Generally avoid dipping 'unagi' (eel) and the cooked vinaigrette tuna
I have tried many soya sauces, and always come back to one as my favourite..
Kikkoman. It has a pleasant flavour (no too strong or salty) and comes in a
convenient bottle. The Yamasa is good too, but may be to intensely flavoured
for some. For Sashimi, consider Tamari soy sauce, it seems to work well and
has a slightly smokey flavour.