This is the first of a two-part excerpt from The Risk Takers: 16 Women and Men Who Built Great Businesses Share Their Entrepreneurial Strategies For Success by Renee and Don Martin.

"Really trust your gut and stay in tune with your gut, even as you continue to grow."
--Sara Blakely

The idea for Spanx first came to Sara Blakely in 1998, while she was preparing for an open-mic appearance at a comedy club. A 27-year-old sales manager who moonlighted as an amateur comic, Sara was planning to wear a pair of white slacks and sexy sandals onstage. She worried that her panty lines would show through her pants. Performing standup comedy is nerve-racking enough without added anxiety about exposed panty lines. So she opted for a do-it-yourself approach: She grabbed some scissors, cut the feet out of a pair of control-top panty hose and slipped them on. "That's when I had my epiphany," she remembers.

That epiphany ultimately made Sara Blakely a multimillionaire. Today, she heads a company called Spanx, with estimated retail sales somewhere around $350 million in 2008.

Instead of placing her clever product idea into a mental storage locker, where it would sit undisturbed until someone else came up with it, Sara quickly took action. She researched and wrote a patent for footless pantyhose. She used her irreverent sense of humor to think up an attention-grabbing brand name and slogan for her product packaging: "Spanx--we've got your butt covered." And with just $5,000 in savings to invest in her business, she designed a new product that, by the end of 2000, was being sold in such major department stores as Saks Fifth Avenue, Nordstrom and Bloomingdale's.

Failing the LSAT Led to a New Career Path
Sara had always pictured herself as an entrepreneur in the making. While growing up in Clearwater, Fla., she learned the value of a dollar early--at her father's insistence. She remembers passing out fliers to parents on Clearwater Beach to drum up baby-sitting jobs. She also organized roller-skating parties at her home and charged admission. She dreamed of someday running her own law practice, hoping to emulate her father, a trial attorney.

At Florida State University, Sara studied legal communications. But her plans for a legal career were derailed when she failed the Law School Admission Test--not once, but twice--and law school was no longer an option. It was a devastating blow, but an experience she now partially credits for her success today. She didn't let adversity or failure defeat her.

"I always feel that failure is nothing more than life's way of nudging you and letting you know you're off course," she says.

After finishing college, Sara worked briefly as a chipmunk at Disney World in Orlando, Fla. Then she landed a sales job at Danka Business Systems, a major office-equipment supplier in St. Petersburg, Fla. She sold fax machines and copiers to businesses, cold-calling her sales prospects. It wasn't her idea of the perfect job, but she learned how to remain tenacious in the face of rejection. When you peddle business machines door-to-door, rejection becomes part of your daily routine. You develop a thick skin and keep on trying, or you simply quit. Sara didn't quit.

"They would personally escort me out of buildings," Sara remembers. "And I also had my business card ripped up in my face probably about twice a week."

She wouldn't let that shake her confidence, though. She got pretty good at charming would-be customers--even those who initially viewed her as a nuisance--and closing sales.

"I learned that you get about 15 to 30 seconds to make an impression, and I learned very quickly that making someone laugh or smile pretty much ensures you'll get another 15 or 30 seconds," the affable blonde explains. "So when you walk in the door of a building with a big sign that says, 'No Soliciting,' you've got to come up fast and you've got to be quick on your feet."

She was eventually promoted to national sales manager and trained other sales reps. She was still working for the company when she launched Spanx.

Seeing a Business Opportunity in a Eureka! Moment
The now-legendary white pants--the ones prone to embarrassing panty lines--had been hanging in her closet unworn for eight months when she finally decided to don them for a comedy club's open-mic night. The footless panty hose gave her the shape and look she wanted. There were no panty lines, she looked a size smaller, and she was free to wear open-toed shoes.

"Like so many other women, I'd buy clothes and get home and really not know what to wear under them," Sara explains. "Everything shows, or cellulite shows, or you just don't feel like it looks pretty. But the moment I cut the feet out of my panty hose, I thought, 'You know what? This should exist for women.' I'd gone shopping. I'd bought the body shapers. They didn't work."

Later that night, when the panty hose started creeping up her legs, seemingly taking on a life of their own, she knew her project needed some design work. But she was confident she was really on to something. She just needed to develop a prototype and bring the product to market. She resolved to just start.

"I was envisioning a totally different life for myself," she recalls. "I knew I could sell, and I knew I could be self-employed, and I knew if I could come up with something for the masses instead of fax machines, I'd succeed."

She received her patent that same year, but she kept her entrepreneurial ambitions a secret. She didn't want friends and family, however well-intentioned, to try to dissuade her from taking the risk. Before long, she knew she would quit her sales job and sink her entire savings into her business.

Ignoring Rejections and Plowing Ahead
When she contacted hosiery mills about manufacturing Spanx, they responded less than enthusiastically. The icy reception, however, left her unfazed. "I cold-called for seven years selling fax machines, and I learned to persevere even in the face of hearing 'no' all day long, which helped me when I had to cold-call the hosiery mills," Sara says. "Everybody told me 'no' for a year straight."

Time and again, she was told footless panty hose were simply a bad idea. The mills were accustomed to producing hosiery designed to improve the appearance of a woman's legs. But Sara was trying to persuade them to manufacture a product that was completely hidden under clothes. "That was so counterintuitive for them," Sara explains. "They thought I was crazy."

Sara was convinced that hosiery material could create a better body shaper. Other body shapers on the market were made of material that was too bulky. The material found in panty hose, though, is like "second skin," Sara says. Given a chance, she knew she could exploit her competitors' weakness and make it her product's strength.

Although her idea bucked conventional wisdom, she persisted in presenting her case to hosiery mills: "Please give me a shot and trust me," she'd say. "This is about the butt. This is a new type of underwear. Don't focus on it being hosiery that is supposed to be seen."

In those early days, she also drew inspiration from an unexpected source: Oprah Winfrey. It happened one afternoon when she was feeling particularly frustrated. "I remember verbally saying, 'I'm asking for a sign,' " Sara recalls. "I flipped on the end of Oprah, and that day Oprah told the world that she had been cutting the feet off her panty hose for years."

Next: Bringing Spanx to market