When Amy Hugo started selling Alberto Parada's minimalist 18k gold jewels in May, she planned a trunk show for June, shortly after returning from JCK Las Vegas. "I like to make a big to-do about welcoming designers to the store," says the owner of the 3-year-old, 700-square-foot Amethyst jewelry boutique in Bethesda, Md. Typically, she hosts trunk shows for new designers within a month or two of receiving their merchandise.Because June is a slow sales month for the shop, Hugo, with the help of three full-time salespeople, had ample time to familiarize clients with Parada, who was present for the entire two-day event. (Out of 2,300 invited guests—700 through email and 1,500 through snail mail—50 people attended the Saturday and Sunday affair.)Hugo cleared out two display cases and three wall units to make space for additional Parada merchandise, which starts at $350 (about 20 pieces a