BLOOMBERG | DRAKE BENNETT

One of the first things fashion designer Tomas Maier produced when he started his own label 19 years ago was a bikini.

It was a natural choice. The line focused on “time off”—something very much on Maier’s mind after 20 years with the punishing travel schedule of an in-demand freelance designer. At the time, he was in the process of moving to Miami, and the inherent challenges of the garment appealed to him: A swimsuit has to function both wet and dry, and it has to flatter with a bare minimum of material.

And for the wearer, swimsuits can be stressful. “For people to get undressed is not easy,” Maier says. Stripping down to a bathing suit is, as he puts it, “an uncomfortable time.” The job of its designer is to reassure.

Today, the German-born Maier is one of the most important designers in luxury fashion—but not because of his bikinis. In 2001 he was hired as creative director of Bottega Veneta, an Italian fashion house best known for leather goods made with an artisanal weaving process called intrecciato. The company had fallen into obscurity and debt when Tom Ford, then creative director of its owner, the Gucci Group, asked Maier to run it. Within a few months, Maier introduced the Cabat, a simple, logo-less intrecciato tote. It set off a feeding frenzy among high-end handbag enthusiasts that continues today. In 2012, Bottega passed $1 billion in sales; the Gucci Group is now called Kering, and its brands include Yves Saint Laurent, Balenciaga, Stella McCartney, and Alexander McQueen. Bottega is the second-largest of them, after Gucci itself.

All along, Maier has continued to run his eponymous label, like a chef splitting his time between a grand palace of gastronomy and a neighborhood bistro (albeit one that happens to be in a very nice neighborhood). Over the years, Tomas Maier—or TM, as it’s informally known inside the company—has expanded from a single store in Miami to locations in Palm Beach, Fla., the Hamptons, and New York City. It sells at Bergdorf Goodman and Barneys and online through Net-a-Porter and Mr Porter. In November 2013, Kering announced a joint venture with the label, investing an undisclosed amount, and a year later, the brand got a new CEO in Giuseppe Giovannetti, formerly an executive with Bottega Veneta. Last year, Maier opened a second New York store and one in Bal Harbour, Fla., and in February he rolled out his first line of sunglasses.

Unlike Bottega, with its 3,400 employees and its ethos of Venetian craftsmanship, Tomas Maier was created from scratch. Maier and his longtime companion, Andrew Preston, wanted to sell the kinds of clothes Maier himself wears: luxurious but functional, cool and comfortable. The brand reflects his temperament, his values, and his remarkably productive love-hate relationship with fashion. “It’s in many ways how the sophisticated fashion consumer dresses,” says Robert Burke, a luxury retail consultant and the former fashion director at Bergdorf Goodman. “There’s a casualness to it. It’s not complicated, and it’s extremely versatile.”

Just after Christmas, I went shirt shopping at the Tomas Maier store on Madison Avenue in Manhattan. I have issues with every button-down I own. Either the tail is too short or the sleeves too long; the chest is too tight, the collar too big. I have pants and shoes I like, and I’m pretty happy with my watch. But a shirt that stays tucked in, that doesn’t need to be pressed, that looks good with or without a sportcoat or over a T-shirt? I’ve been looking for that for a while. If I lived in L.A., I might obsess over cars; if I lived in ancient Egypt, I might have fixated on tomb design. But I live in New York, so I think a lot about things like shirts.

So does Maier, of course. Even among fashion designers, he’s famously meticulous. Walking through his Palm Beach store, he takes a cashmere sweater off the rack and turns it inside out to show me how it was knitted without seams down the arms, using a special machine so nothing will interrupt the wearer’s feeling of arm-encircling softness.

The clothes are expensive—men’s cashmere sweaters are $875, cotton shirts $295, chinos $485—yet Maier says he’s aiming for “the lower spectrum of the design world.” The term industry analysts use is “accessible luxury.” The prices, Maier says, reflect that his clothing is made not in the Third World but in Italy, in the sort of workshops that have special seam-obviating knitting machines. The prices would be even higher if he didn’t eschew runway shows and ad campaigns, and they are at least within the same realm as mass-market brands. You can, after all, spend $150 on a shirt at J.Crew. Maier says you should just wear your Tomas Maier shirt twice as often.

Maier himself does something like this, though not for financial reasons. He wants to limit how much he thinks about the clothes he wears, something that at first sounds odd coming from someone who makes clothes for a living. But Maier doesn’t want to worry about fashion when he doesn’t have to. “I would rather sit and read the paper for 10 minutes longer than figure out some elaborate outfit in my closet,” he says. He buys multiples of the same few garments: dark jeans or chinos; white or light blue shirts; navy, dark gray, or black sweaters. “And that’s it.” He pauses. “Occasionally there’s an army green.”

The day we meet in his design studio in Delray Beach, Fla., is one of those occasions. He’s wearing an army green fatigue jacket over a charcoal tank top and dark, slightly faded chinos—all from his own line—and black Nike running shoes. Delray Beach is an unlikely place to find Maier. Twenty miles south of Palm Beach, it’s full of wealthy retirees, but it’s also home to dozens of halfway houses, making it the rehab capital of the U.S.

Maier ended up here somewhat by accident. At 19 he’d fled Pforzheim, the small southwestern German city where he grew up, to study fashion in Paris at the Chambre Syndicale de la Haute Couture. He worked for fashion houses such as Hermès, Sonia Rykiel, Guy Laroche, and Revillon, but it was exhausting. “I would fly to Italy on Sunday night, work in Italy Monday and Tuesday, come back, work in Paris at one place on Wednesdays, work at another place in Paris on Thursday, work at another place in Paris on Fridays,” he says. The following Monday it would be off to central France to work in a client’s factory. “At some point I said, ‘I have to change my life,’ ” he recalls. “And that’s when I started to think about doing my own thing, very small.”

Maier had already been talking with Preston—an American who had worked in Paris for the U.S. Department of State—about starting a fashion line. With Preston handling the business side, they showed their first collection in Paris and Milan in 1998. The Venezuelan entrepreneur Carmen Busquets, a founding investor in Net-a-Porter, met Maier and Preston at the apartment that doubled as their showroom in Paris. She fell in love with the bathing suits and the cashmere wraps Maier was making to go with them. “I spend a lot of time in the Caribbean, I love to be in nature and I live in Verbier,” she said via e-mail. “If I go for a 7 a.m. or 6 p.m. swim, you don’t want a dress; you want a towel and cashmere! Nobody mixes luxury and lifestyle like Tomas.”

In 1999, Maier and Preston moved full-time to Florida. Miami had always fascinated the designer—the architecture and chaos and seediness. “It was a danger zone,” he says. “I liked the geography of it, and I liked the mix of different people that had to get along. I found it very cosmopolitan in a way, like the future.” Miami’s actual future was mostly garish hotel towers and condo developments, however. When it arrived, Maier retreated to Palm Beach County, which was far enough away from Miami for his sensibilities but close enough that he could still get quickly to an international airport.

He lives a hermetic life when he’s in Florida. He’s either in the Delray Beach studio or at the home he and Preston own nearby—he also has houses in Montauk, N.Y., and on an island off the coast of Maine. Maier bought the studio, originally an industrial bakery, from the Cuban artist Enrique Martínez Celaya, and the concrete floor is still gridded with paint. In the kitchen there’s a Julian Opie print of a woman stripping off her clothes, her face a blank circle. “I love to retreat to this space, because there’s no distraction,” Maier says of the studio, where he will bring creative teams from both Bottega and Tomas Maier. “They love to come here, because once we’re in here, the door is closed and we’re in this big space and we just work. We order lunch in, a salad or whatever. It’s very focused,” he says.

Maier is dismissive of designers who rely on recognizable flourishes. “I never do collections that have themes. I hate that,” he says. “ ‘Oh, it’s a movie,’ you know. ‘It’s inspired by a trip to Bhutan.’ Some crap like that.” Against one wall in his studio are two giant “mood boards,” the starting point for every collection. In mid-December they’re pinned full of photos: a 1920s skier, a Scottish lord in his tartan, a gamin in penny loafers, an old burgundy-plaid car interior, a young Asian man with a close-shaved scalp and a baggy sweater, an art-cluttered room with a blazing hearth.

The boards, Maier believes, allow him and his team to pick out the currents in his clients’ ever-shifting taste. “It’s mostly very abstract,” he says. Do people want rounded shapes or angular ones? Are they thinking about nature or the urban jungle? How adventurous are they feeling? “Would people rather stay home? Or is it more like they want to explore, because they haven’t been traveling for too long?” he asks.

Maier is, at heart, a preservationist. He isn’t afraid to revisit clothes from previous collections and build off them. “To his credit, he is unaffected, he is the same Tomas I met years ago,” writes Busquets. “We often meet up in Miami, Paris, Milan, New York, and Capri. I tell him, ‘Tomas you need to do Tomas Maier hotels, they would be amazing!’ ”

Maier’s Madison Avenue store occupies the bottom two floors of a 19th century town house with a 1920s art deco facade. The floor is pale oak, and light floods in through a quartet of two-story-tall front windows. Between the racks, in bronze vitrines and on dark wood shelves Maier designed, are books on the architect Louis Kahn, limited-edition Diptyque candles meant to evoke the scents of Montauk and Maine, and earrings from the Milanese jeweler Osanna Visconti di Modrone. Near the door are two Stone Age-style fertility statues, each the size of a child, that French furniture designer Christian Astuguevieille made from coiled rope. There isn’t actually much clothing on display.

Creativity for Maier is a matter of time management. He divides his schedule into weeklong chunks—a week for an upcoming Tomas Maier men’s show, a week for an upcoming women’s show, a week for the furniture line or fragrance he’s developing for Bottega. He does this both to allow time to immerse himself in a project and to give the employees working on it his undivided attention.

For Maier, luxury, too, is a matter of time. He hoards spare hours. “I have to be very organized, to know ahead that, ‘OK, Saturday, I can go to a museum,’ ” he says. The son of an architect, he plans trips around buildings he wants to see. He’s been trying to get to New Haven to see the ice rink and art galleries Eero Saarinen and Kahn built at Yale. He hired the Japanese architect Toshiko Mori, whose spare style matches his own, to build his house in Maine.

In photographs, Maier can look stern, but in person he comes across instead as shy. His clothes are for people who, like him, would prefer not to be the center of attention. “If you don’t feel comfortable around yourself, you don’t come over right, either,” he says. “I like to give men—and women—just that little extra something, that thoughtfulness. The proportions are right, the coloring. It’s the right silhouette but without looking like they want to make a statement through their clothes. You make a statement through who you are and what you’ve got in your brain, right? That’s how you make a statement.”

There’s a character in an Alice Munro short story who, feeling her age, decides to freshen up her look. But she warns herself, “You have to watch out, even in these garish times; you have to watch for the point at which the splendor collapses into absurdity.”

That line sticks with me in the Madison Avenue Tomas Maier store—the unspoken contract he makes with his clients is that they will never look like they are trying too hard. Although his current collection does include a few pieces—a zip-front green-and-purple velvet sweatshirt, for example—that could make a pretty loud statement, for the most part the clothes exude a muted richness. To keep the racks uncrowded, the shirts are kept in wide oak drawers. Customers are encouraged to pull them out on their own, imagining they’re at home deciding which of their many artfully rumpled shirts to wear. I try on a blue oxford. The back is darted so it doesn’t blouse. It doesn’t cling. It is, as promised, the right silhouette. The only flourish is the Tomas Maier logo, a salmon-colored palm tree near the front hem. When I tuck the shirt in, it disappears.