What to carry depends on what you like and what you think will sell. "I gave 100 people a list of products and asked which they would buy," Rizza says. "Most people said sunglasses. I determined sunglasses appeal to a variety of ages."
The next step is choosing a cart. Carts come in many sizes and styles with varying capabilities. There are carts for specific types of food, some with refrigerators, grills, steamers--even small ovens to bake on location.
Determine your needs before ordering a cart, says Jeffrey Morris, president of All A Cart Manufacturing Inc. in Columbus, Ohio, a cart design and manufacturing company. "List your products and the equipment required to make or display them," he says. "Also draw a simple layout of the cart to give [the manufacturer] an idea of size requirements."
Think versatility, especially with food. Don't limit yourself to making one item, in case it doesn't sell well and you have to switch gears.
"What sells might be completely opposite from what you thought," says Gerardo Gonzalez, director of food service at the Statue of Liberty in New York City, which has several carts, and president of Gonzalez & Associates, a Piscataway, New Jersey, company that consults on mobile merchandising and food-service start-ups.
You can get a good deal on used carts, but Clark, who also sells custom-designed carts, urges caution. "People buy a cart they think is cute--only to find out they've purchased someone else's headache," she says. "It ends up costing more to modify than to buy new."