Roll the contents into the rice and seaweed by hand, and then find a clean thing to press out the square shape. Don't press it too hard. From experience, I once forgot to bring a bamboo curtain to work, wrapped the newspaper with plastic wrap (of course, wrapped it tightly) and wrapped more than 100 rolls. The practice of external volume:

A piece of laver, folded in half and divided into two pieces. Take half of them and look carefully. The laver is divided into two sides, the smooth side faces down, and the rough side is evenly coated with rice. The dosage of rice: hold a rice ball slightly smaller than the palm of your hand in your hand and put it in the center of the laver, pushing it from the inside out and from the middle to both sides. If your hands feel sticky, you can moisten them with some water.

After the whole laver is covered with rice, sprinkle some white sesame seeds in the middle, then turn the laver over, coat it with a little green mustard in the middle, and then put something you like. Now it begins to roll.