Click the ingredients for the requested sushi (as shown in the recipe book) and then the green mat to make each piece, clicking the correctly colored plate to add it. When a plate is ready, drag it to the belt for the customer to pick up.
For noodle orders, click the ingredients and then drag the bowl to the serving plate and then to the customer. Drag customers' sake on a serving plate to improve their mood.
Don't forget to clear plates as customers finish with them and collect money when they leave!