1. Choose Wisely

Anyone who's trolled around on eBay knows that they can find everything from blenders to toilet paper. But peddling mundane household products isn't necessarily a winning strategy. The best eBay businesses sell unusual, hard-to-find items at a discount, says Marsha Collier, author of 'eBay for Dummies.' By sticking to this approach, you'll cut down on the competition and the ensuing price wars that could eat into your profits.

Fortunately, you don't need to know anything about antiques and collectibles to fulfill Collier's requirements. One idea is to look for items unique to your region and sell them at a discount. If she lived in Manhattan, for example, Collier says she would regularly shop at Century 21, a famous designer discount store, and then resell the hard-to-find name-brand clothing at a markup on eBay.