1. Choose the right developer. Greenwich Jewelers’ Jennifer ­Gandia met with six companies before partnering with Dotbox, also in Manhattan. She wanted a firm that could help her maintain a seamless experience between her website and the F Shop.2. Make the F Shop look good. Some shops can be flat-out ugly. This isn’t the case with Gandia’s, which is simply designed with plenty of white space. “It’s very important for a ­jewelry brand to present merchandise in a very attractive, on-brand way,” says Dotbox’s Zo Bjorgvinsson.3. Know that sharing is good for business. Understand that “likes” can influence “buys.” Says Bjorgvinsson: “Seeing what your friends like not only influences your purchases, but also makes it even more fun to shop.”4. Experiment with price points. Jewelry in Gandia’s F Shop starts at $60 (for Miguel Ases cherry quartz earrings); pieces in