I have given a nigiri-sushi(or nigiri-zushi )party this weekend. My friends have came to my house and made Nigiri-sushi together.
Prepare sushi rice first. Then put about one tablespoon of sushi rice on your palm and squeeze it into a rounded rectangular shape. Then spread a small amount of Wasabi on it.
Put it aside on the dish.
Put one slice of avogado and shrimp on your palm. Place the formed rice back on them in your palm.
Bending your palm to hold them. Slightly squeeze the rice and a slice of avogado and a shrimp again.