You can reduce the risk in starting your own small business by sticking closely to what you already know. By “what you know,” I mean (1) the product or service you are selling and (2) the primary method by which you are going to sell it.

Serially successful entrepreneurs follow this formula. They spend thousands of hours figuring out how a particular business works—and once they understand it, they seldom jump into something entirely different.

My own rule for starting a new business is this: One baby step at a time. By that, I mean that I’m willing to try something new—but just a little new. If, for example, I’ve learned how to sell cat food with banner ads on the Internet, I might consider setting up a business that sells cat food with small ads in magazines. (That’s one baby step. If I can’t figure out magazine advertising, I can get out quickly and safely.) But I wouldn’t let myself get into a business that sold cat health-care products through direct mail—even if I could convince myself that I’m an expert in selling cat products. Selling cat health-care products through direct mail is simply too many steps away from my core competence.

If you develop expertise in a particular business and don’t stray too far from it, you’ll always feel confident that you can create a new business without taking a lot of risk.