Walking into the Aviator Nation store on Abbot Kinney in Venice is like stumbling into a frat house with a feminine touch. Steely Dan, Doors and Grateful Dead album covers and vintage skate decks nailed to the walls, a record player spinning Aerosmith's "Sweet Emotion," a "720 Degrees" arcade game in the corner, stacks and stacks of foam trucker hats, T-shirts and hoodies spreading good vibes like "Pray for Surf" and "California Is For Lovers".... It's such a sensory experience, you half expect your shoes to be sticking to the floor from last night's kegger.

Aviator Nation is the vision of Paige Mycoskie, who is turning a passion for 1970s nostalgia into the next California lifestyle brand.

"This is my little oasis of awesomeness," says the designer, 33, the picture of surfer girl blondness dressed on a recent afternoon in her signature uniform of checkerboard Vans, cut-off jean shorts, aviator sunglasses and an Aviator Nation tank top. "I hope people leave in a better mood than when they came in."

In just seven years, she's gone from sewing up T-shirts in her bedroom to designing a full brand of men's, women's and children's clothing and accessories that generated $5 million in sales last year, plus two freestanding Aviator Nation boutiques and a mobile Aviator Nation store housed in an Airstream trailer that will be cruising Orange County all summer.

While most T-shirt companies use computer-generated graphics and artwork, Mycoskie hand draws the lightning bolts, rainbow stripes, big wave surfers and psychedelic maidens that decorate many of her designs, then scans them into the computer. The slight imperfections lend an authenticity to the line, which also includes snowbunny-style pom-pom hats, reversible cord puffer vests, fleece sweatpants, and dolphin shorts made from dead-stock Hawaiian shirt fabric, all in vivid bright colors and all of which bring to mind OP, CB Sports and other lovable surf and snow labels of yore. The gift-with-purchase Aviator Nation drink koozie is the perfect loungin'-by-the-water, good-ole-girl touch.

"Everything I design or put in the line is something I personally want," she says of the collection, much of which looks like it could have been swiped from a cool older brother's closet. "I don't look at trend reports or runway shows. I'm not in that world."

"She's an original, a true bohemian who understands men's [clothing] as well as women's, knows how to have something for each and how to blur the lines a little," says Jim Moore, creative director of GQ magazine, which named Mycoskie one of its best new menswear designers in America for 2013, an honor that includes the opportunity to collaborate with Gap on a capsule collection that will be sold in Gap locations worldwide. "I always urge young designers to pull every penny together and open a store as soon as they can," he says. "That's what she did, and it became her laboratory."

A native of Arlington, Texas, Paige Mycoskie grew up the middle child between two brothers. Her older brother Blake Mycoskie founded Toms Shoes on the model that for every pair of shoes sold, a pair is donated to someone in need, and her younger brother Tyler Mycoskie works in sales at Toms.

She was always into sports, waterskiing and playing on the volleyball team, but also happened to have an artistic streak and a penchant for rainbows — rainbow window blinds and switch plates in her bedroom, rainbow birthday cakes, Rainbow Brite dolls, rainbows on every drawing that ended up on the family's refrigerator. "All of the artwork I did as a child was basically the same stuff I'm doing now, but not as perfect," she says.

Going into business for herself wasn't out of left field. She showed entrepreneurial skill at a young age, figuring out that the best place to set up her lemonade and cookies stand for the summer was on the edge of the golf course where her grandparents and their friends played every day. She took home as much as $500 a day — as a 6-year-old.

She first came to L.A. for a summer internship at Shape magazine and returned in 2002 when she was cast, along with her brother Blake, in the second season of the CBS reality show "The Amazing Race." They came in third place on the show, ultimately missing the $1-million prize. Afterward, she moved to L.A. permanently, settling in Venice, and working as a freelance writer and a saleswoman at the Santa Monica surf shop ZJ Boarding House. She got the idea to make T-shirts after noticing the vintage ones that were a mainstay of her tomboy chic wardrobe were becoming more expensive and harder to find.

"My idea of dressing up still to this day is wearing a rare rock tee with jeans and cool shoes and a leather jacket," says Mycoskie, who has been collecting vintage T-shirts since age 14. She only buys originals, numbers her collection in the hundreds and includes among her favorites a Jimi Hendrix "Just Ask the Axis" tee from 1970 and Live Aid festival shirt from 1985.

"It dawned on me I should start making shirts like the vintage ones I liked," she says. "I have always been a 'figure it out' type of person, so I bought a how-to book on sewing, a how-to DVD on screen printing, and used $150 my grandmother had given me for my birthday to buy a sewing machine." Because she couldn't find a multiple color screen press that was affordable, she sewed colorful strips of fabric onto the shirts to create rainbows and stripes that way. Those first pieces must have had a homespun charm, because whenever she wore them, she got attention. "One day, when I was out and got asked about my shirt three times, I thought, 'OK, I could sell these,'" she says.

So she quit her job, moved back to Texas to live rent-free with her parents, and set to work on a sample line. "I sewed all day and night," she says. "I would turn on music and the time would just fly. It wasn't work, I was enjoying making clothes and being creative."

The name of her company, Aviator Nation, is inspired by her love of aviator sunglasses. "When you put on a pair of aviator sunglasses, you immediately look cool," she says. "Aviators are also something that will never go out of style, like a T-shirt. And I wanted my brand to be about bringing people together. And that was what was happening. I was wearing the clothes, and cool people were coming up to me, and asking me about them."

After she had 40 pieces, she headed back to L.A. She took her shirts to Fred Segal in Santa Monica, showed them to a salesperson, and before she had even left the parking lot, the buyer was calling with a $3,500 order. The next day, Planet Blue in Santa Monica placed an order. "From the moment I saw Aviator Nation, I was struck by her use of color and fabrics," says Patrick Thompson, the men's buyer there. "The brand personifies everything wonderful about California beach life."

She stopped when she had three stores, and then got down to sewing, dyeing and washing the shirts. "I did it all from scratch," she says. The first deliveries landed in stores in February 2007, and sold out in weeks. One thing led to another, and now she has 120 retail accounts, most of them small boutiques except for Bloomingdale's, and her own factory south of downtown L.A. producing four collections a year.

"Over the course of all this, I saw it as an opportunity to have fun, make clothes and employ people in the USA," she says. Because the clothes are produced locally, they are not inexpensive; prices range from $35.99 for a hat to $139.99 for a hoodie.

She opened the first Aviator Nation store in Venice in 2009, in a building that used to be an art gallery and before that an auto body shop. Out back are her office and design studio, as well as an outdoor space with a stage for music performances, a pingpong table and plenty of room to hang out.

"Her talent lies in creating a retail experience as much as in design," says her brother Blake, who opened the first Toms store last year, just down the street from Aviator Nation on Abbot Kinney.

"We talk about business a lot because we're both in love with our companies," Paige says of her brother. "It's the topic of conversation 90% of the time when we are together. But we have different ways of doing things. I'm real slow and steady, and very particular about keeping it authentic, not rushing into everything and not selling to everyone who knocks on my door," she says. "Blake's in a different business. He wants to sell as many shoes as possible to give away as many shoes as possible."

They have both built their companies without partners or outside investors. And next spring, they will collaborate for the first time on an Aviator Nation for Toms line of shoes. It's just one in a series of product extensions in the works.

"Some day, I would love to have a full line of Aviator Nation lifestyle products including luggage, wetsuits and swimwear," Mycoskie says. "But I'm taking this one season at a time."

booth.moore@latimes.com