NEW YORK - LaQuan Smith is all about the champagne lifestyle — bubbly, luxurious and, especially when it comes to the women’s clothes he creates, sexy.

The designer made his New York Fashion Week debut at 21 with a sleek and sassy collection he dubbed “Water Goddess.” Ten years later, his rise seems meteoric in fashion years, from sneaking into industry events and handing out wildly colored and textured leggings he sewed in his Jamaica, Queens, basement to outfitting Beyoncé, Serena Williams, Jennifer Lopez, Kim Kardashian and Rihanna.

At 31, some see the self-trained Mr. Smith as a pioneer in pushing the fashion culture forward, but it was far from easy. He said in a recent interview that he owes his success to his singular passion — fashion — and staying true to himself by trusting his gut.

“It’s just by doing what I love, just doing things that speak and represent me,” said Mr. Smith, dressed in a killer red-and-blue plaid jacket, turtleneck, ripped black denim jeans and pristine white kicks. “I always like to start with a level of authenticity.”

That authenticity was in play Oct. 15 when Moet & Chandon named Mr. Smith one of its “Nectar of the Culture” ambassadors, along with other trailblazers in music, art and more, in celebration of Moet Nectar Imperial Rose. It’s the latest in a long line of collaborations as Mr. Smith continues to build his namesake brand, sticking close to home to produce his clothes in Queens.

“New York used to be the primary source of garment construction, and that’s something that I wish we could sort of go back to,” Mr. Smith said. “Manufacturing in Queens is just something that organically happened.”

Some of Mr. Smith’s lows struck early in life, after his grandmother taught him to sew when he was 13. After putting on a fashion show at his middle school, he was thrilled to attend the High School of Art and Design, only to say goodbye to bustling New York in the 11th grade when his mother moved the family to Delaware, a place that held no allure. It was then that he was diagnosed with bone cancer, a truly “humbling experience,” he said.

Mr. Smith recovered and continued to pursue his fashion dreams, desperate to return to New York, but he was rejected by both the Fashion Institute of Technology and the Parsons School of Design.

“I was just kind of devastated and at a loss. I didn’t really know how to get my head up off the ground,” he said.

That’s when he was offered an internship at BlackBook, the art and culture magazine, working for then-fashion director Elizabeth Sulcer. She was in demand for industry parties and events, and Mr. Smith made use of those contacts, showing up uninvited at times dressed in his own designs. He took to handing out his leggings to whoever would take them.

In 2010, the effort paid off when he spotted Lady Gaga in a pair as he flipped through a tabloid while with his mom at a supermarket.

“My mom was, like, ‘Yeah, that’s nice,’ ” he said. “I don’t think she really got it.”

The same year, Mr. Smith showed for the first time at fashion week and American Vogue’s former editor-at-large, Andre Leon Talley, chatted him up. Also, Rihanna wore his gold chain-mail bodysuit in her “Rude Boy” video and later shouted him out on Instagram for his “money green,” barely there net dress she styled over a bikini in Brazil.

“I was 21 years old and I had such an incredible amount of support from industry insiders, and then a couple years after that, it sort of was like a crash and burn, where reality started to hit me,” Mr. Smith said. “I had no business infrastructure. I had no money. It was just popularity. ... It took time for me to be able to focus on, really hone in on, running a solid business.”

It took time and the help of business partner Jacqueline Cooper, who remains by his side.

As a designer who is African-American, Mr. Smith is a rarity in fashion. Diversity and inclusion in the industry is a persistent problem, he said.

“I always tend to feel, I don’t know, maybe pigeonholed sometimes,” Mr. Smith said. “I like to be introduced as a designer, not an African-American designer. It doesn’t mean that I’m ashamed of who I am. It’s just that, when it comes down to my profession, why is skin color introduced first?”

As a company, he’s a man of action, making broad use of Latina, black, Asian and curvy models to walk his runways. His custom business remains robust and he brings the same inclusive zeal to the range of bodies that belong to his private clients.

“My goal is, if you want to feel sexy, if you want to look fabulous, if you want to be the center of attention, that’s LaQuan Smith,” he said. “That is something I want to continue to embrace.”