There was a time when the fashion industry was about as open to outsiders as is Yale University's Skull and Bones secret society. There was one path to becoming a respected designer, which was studying at a prestigious art-and-design school, fetching coffee for difficult designer bosses in New York City, Paris or Milan, then courting the press and moneyed investors to start a label.

In recent years, the fashion community has tried on meritocracy for size, acknowledging talented interlopers with more entrepreneurial spirit than formal training. Three of the most promising new labels to crack the code are Los Angeles—based Rodarte and Des Kohan; and Libertine, based in L.A. and New York. Each of them has been either adopted by editors, admired by the masters or promoted by stylists. All of them are proving that the best-made clothes will have an eager audience no matter where or how they're created.

When the Rodarte (pronounced Row-dar-tay) designers, sisters Kate and Laura Mulleavy (26 and 24, respectively) arrived at the Women's Wear Daily offices in New York with their weeks-old collection of mostly bias-cut dresses last February, they had no idea what to expect. They had exchanged phone calls and e-mails with Cameron Silver, owner of the vintage boutique Decades, in West Hollywood, who took them under his wing and made some connections with the press and retailers. Yet they knew next to nothing about the business and only packed up their dresses and headed to New York after some prodding from a Neiman Marcus buyer.

"We were clueless when we went in there," says Kate, who does the illustrations for their line. "Someone interviewed us forever. They took our picture. Two days later, we were on the cover."

Not bad for their first meeting. The media have gravitated to the University of California, Berkeley, graduates—who live in their grandparents' guesthouse in Pasadena as they scrape together money for their business—because of their talent, sure, but also because of their enthusiasm and naiveté, the stories they tell about their eccentric family and their deep respect for design in all its forms.

Being outside the system, they believe, helps the Mulleavy sisters maintain their passion and keep their ideas fresh. At the time of this interview, the two had stayed up all night boxing and shipping their first orders to high-end boutiques like Kirna Zabête in New York and Susan in San Francisco.

"It might be more traditional to be an intern for a designer or something," says Kate. "But that wide-eyed approach and our eagerness are things that I'm not sure we would have had if we had been to fashion school."

The press has certainly been kind to Libertine too, but what really blows its designers away is the attention they've received from their new friend, Chanel designer and fashion polymath Karl Lagerfeld.

"I'm shocked and amazed when I hear that he likes what we do," says Cindy Greene, 35, over the phone from her New York design studio. Greene, along with Johnson Hartig, 35, created Libertine, a line of retooled vintage clothing with images silk-screened onto the fabric. "Having him come to the studio and buy so many things for his friends, try on so many things, it was an absolute honor and a dream."

Greene, an Ohio native, graduated from art school as an experimental filmmaker, was a member of the band Fischerspooner and has worked as a graphic designer. Hartig is from Los Angeles, was a commercial actor, has been a lifelong Anglophile who once assisted a decorator and just finished a decorative-arts study program with the Attingham Trust in England.

Four years ago, when Greene was working for DKNY, and Hartig was selling reworked vintage clothes to Maxfield and Fred Segal, the two were introduced by a friend. Greene screened an image of a gorilla onto the back of an old shirt and sent it to Hartig as a present. He altered it to fit him better—using his signature exposed stitching—and wore it to a party. Interest was piqued. Fred Segal placed an order. The shirts sold out in one afternoon.

Libertine, says Hartig, is now sold in 23 stores internationally, and has inspired a legion of knock-offs along with high-profile admirers. To stay ahead of the imitators, Greene and Hartig are considering creating a new line, for which they will manufacture instead of recycle vintage clothing.

"If I don't know how to do something, I just wing it," says Hartig. "Sometimes I do look at fashion students and say, Why are you bothering? I taught myself didactically."

Desiree Kohan, 29, designer and owner of the new Des Kohan boutique in Los Angeles, got a peek into the fashion infrastructure while she worked as a trend forecaster in Milan.

"All of my friends there worked for the top designers or in showrooms," Kohan says, perched on a chair in her gallery-like store with warm rose-tinted concrete floors. "Once, I was visiting my friend who worked at Prada, and Miuccia Prada asked me to take off my jeans so she could Xerox them and study the stitching."

Kohan studied sociology and psychology at UCLA before she left for her stint in Italy, where she worked free-lance for the likes of Marc Jacobs Shoes, scouring flea markets for inspiration. And her affiliation with celebrity stylists—Negar Ali (Beyoncé and Naomi Watts are clients) and Lysa Cooper (Jessica Simpson, Gwen Stefani and Paris Hilton) and her sister-in-law's father, Max Azria of BCBG—has proved to be beneficial to her design-and-retail business.

"When you see what's in the stores, by the time it gets there, those ideas are old," Kohan says. "The designers came up with these ideas three seasons ago, and by the time it's available to the public, they're on to the next. When I was a trend forecaster, I had to be 10 steps ahead, to keep things superfresh. So I'm applying that same idea here. I've been approached by every high-end boutique and department store to carry my line, but I've decided to keep it small. That way I can have an idea and then the clothes will be produced in a month."

For example, when her stylist friends say they can't find the perfect belt, Kohan has a local artisan make it. Her tight collection of knit separates and dresses in soothing neutral tones ($500-$800) is unique but doesn't look like "origami," she says. It's all produced locally and shares rack space with Hussein Chalayan and other celebrated local designers, including Pegah Anvarian and Jasmin Shokrian, both longtime friends.

To Kohan, it's easy, and the confidence she has in her taste is reflected in the well-edited collection in her store, even without a degree from Parsons or the Royal College of Art hanging on her wall.

"I didn't study anything to do with fashion. I wanted to get a formal education and learn about the world," she says. "If you're a designer, you're a designer, with or without the training. I designed the store myself. I even designed these chairs we're sitting on. It's in everything you do."