Even when a customer is not actively waiting for a certain item, always start processes if you have the correct pieces. Keep your wheel moving and cleared out as much as possible in order to be at maximum efficiency. Particular customers will always order the same thing. Have that item ready beforehand. When that customer appears, quickly spin the wheel to give them the correct item, and you should earn gold coins from them. As you progress, you additional recipes will become available. The first one allows you to turn fish into sushi by using the chef and the knife. When you get the option for advanced processes, the customers in those levels will never order the original item (for example, the fish). It is safe to make all the advanced items immediately and not save the lower tier ingredients.