Sandra Bullock and Christina Aguilera not only wed their one-and-onlys, they wear one-and-onlys on their left hand. But you don't have to be a star to get a custom-made style. Many jewelers offer this service, often for an afforable price. Intrigued? Find a reputable designer, such as those featured on these pages, whose collection you like, and discuss price up front. And be patient: It can take four months to get a solitaire as singulary chic as these.

Left: 6.18 carat Asscher-cut diamond with .60 carats of trapezoidal side stones and .25 carats of round brilliant diamonds in platinum, Beaudry, price on request; 877-232-8379.