Fashion and jewelry go hand-in-hand, yet few women think of their local jeweler as a place to find fashion-forward jewelry. That's because few jewelers understand a key element of the fashion business. Retail management consultant Kate Peterson, of Performance Concepts, Montgomery Village, Md., explains: "Most jewelers don't have a handle on fashion, because it's a seasonal business and they're afraid of it and don't know how to sell it," Peterson says. She acknowledges that trendier jewels have a shorter shelf life than, for example, bridal jewelry, but she says jewelers who don't embrace fashion will miss a huge part of the market. Selling seasonally doesn't mean drastically discounting merchandise to make room for new goods at the end of each season, which is the practice in the apparel business, says style consultant Michael O'Connor, of Style & Substa