Best of all, the consulting business model itself is a breeze. With consulting, you can start immediately with just a cellphone and a laptop. A lot of other businesses, like eCommerce, require a lot more from you.

Typically, the best time to start a relationship with a lawyer is before you start your consulting business. Too many people make the mistake of forming a company and reaching agreement among co-founders without consulting a lawyer.

Editor's note: This article was excerpted from our Consulting Business start-up guide, available from the Entrepreneur Bookstore.. The dictionary defines a consultant as "an expert in a particular ...