Pop into any upscale coffee shop on Los Angeles’ affluent Westside, and you’re bound to bump into a jewelry designer. Jewelry is the art du jour in many major cities, especially L.A. But even in a town packed with ­people turning out baubles, Susan Foster stands out. 

The designer and retailer, who opened her eponymous business in 1999 while in her 20s, not only creates one of the most reliably glamorous fine jewelry collections on the Left Coast, she also operates a beautiful shop, in the ultimate la-la-land neighborhood of Brentwood, curated carefully with her line and a handful of equally sophisticated collections: Coomi, Carla Amorim, Federica ­Rettore, and Borgioni.

Foster was initially inspired to get into jewelry design after watching a jeweler neighbor repair a prized necklace for her.

“It was a great time to be a young jewelry designer and start a business because the market wasn’t saturated with designers the way it is now,” she says, referring to the collection’s early days. “There were a handful of chic, esoteric designers during that time and it was a great period to get in, make my mark, and establish myself.”

The collection quickly became a favorite with Hollywood stylists and celebrities; Minnie Driver appeared on the cover of Mademoiselle wearing one of Foster’s pieces when the designer was only a year into the business. Renée Zellweger, Megan Fox, Leslie Mann, and Mila Kunis are among the many celebs who’ve worn Foster’s creations on the red carpet.

Foster started out working with silver, but slowly built up to more luxurious materials. “After each collection sold, I would reinvest little by little in more high-end materials,” she says. “Silver eventually became gold-filled, then 14 karat, then 22 karat, then ultimately platinum and diamonds. I was always in pursuit of the best—that has been my impetus.”

Her aesthetic feels thoroughly modern, while paying homage to iconic ­jewelry looks. Design nuances borrowed from the Art Deco, Edwardian, and American Modern eras pervade.

When asked about her place in the Los Angeles market, as a designer and retailer, Foster is refreshingly blunt: “I will say straight off that the whole super-casual L.A. rich hippie look some stores still carry is completely passé. My mission is to design exceptional quality, chic jewels that are above and beyond.”

Still, she readily admits L.A. can be a tricky market for jewelry. “Women here, most of the time, dress casually,” she says. “They’re not walking around wearing Buccellati cuffs, as opposed to, maybe, women in New York.” But Foster adds that her clients tend to be world travelers who frequent destinations “that aren’t so casual.”

Her well-heeled clients aren’t the types to go for overt marketing messages or flashy promotions, so she doesn’t do any real advertising around the holidays. Still, she stokes seasonal sales with an annual bash, which she characterizes as “a fabulous holiday party where we invite our clients to see the new collections while they sip Champagne and enjoy hors d’oeuvres.”

And when new inventory comes in during the busy season, the retailer and staff call clients “to let them know we have something special and specific for them.”

She predicts colored gemstone styles “coordinated with colors off the runways” will be strong sellers this year. And big cocktail rings and long necklaces—made popular by Jennifer Lawrence and other celebs on recent red carpets—are among the looks she’s created and purchased for the season.

For Foster devotees, bold always sells well. “I design for a woman of any age who has a total belief in herself. [A woman with] an effortless, fearless ease…and confidence.” That, adds, the designer, “is the most beautiful type of woman.”