How to dip soy sauce ?
To separate sushi rice and fish is a violation.
Pick up one side of sushi with your thumb,
forefinger and middle finger, dip the other side slightly into soy sauce.
http://www.japaneserestaurants.co.nz/more/best-way-to-eat-sushi/
Do not dissolve Wasabi into soy sauce when you eat Sashimi, it is impolite behavior in manner.
Eddie
Japan