Fast and easy cash
Simply give cheese and sauce pizzas to everybody, some customers may be upset and ask for a refund, some are forgiving. Your costs will be significantly lower because you're using less toppings and you'd profit alot.
Various General Tips
To make a supreme pizza you'll have to put every ingredient on it - sauce, cheese, pepperoni, sausage, olives, onions, mushrooms, and bell.
In order to make a veggie pizza you'll need to have all of the vegetable toppings or your customers will be unhappy.