Sara Blakely is pretty amazing. She's the founder and inventor of Spanx and a self-made billionaire. She even still holds the original patent for her game-changing women's underwear.

There are a decent number of self-made billionaires now, and some incredible women entrepreneurs. What sets Blakely apart? For one thing, she bootstrapped her company to hundreds of millions of dollars in revenue, taking no outside investment. That's something very few iconic founders can say--not Jeff Bezos, not Bill Gates, not Steve Jobs, not Elon Musk, not Sheryl Sandberg, not Mark Zuckerberg, and not many others. 

Recently, Blakely sat down for a nearly hour-long on-stage interview with Inc.'s president and editor in chief, Eric Schurenberg. Afterward, Schurenberg pronounced Blakely "a badass," which I can assure you is high praise. 

Here are the things that Sara Blakely says have been the keys to her success. If you have a daughter (or a son for that matter, but given what's going on in the world, let's focus on our daughters), this is advice she will benefit from.

1. Do the "pre-work."

Blakely talks about doing the "pre-work," which mainly involves all the things she did to develop her entrepreneurial mindset long before she even knew what her entrepreneurial dream would be. We'll talk more below about this, but it's worth isolating the top areas of development right up front. As Blakely describes it, her pre-work involved two key things:

  • "practicing visualization--manifesting the things I want in my life," and
  • "finding courage, building courage."

Remember: visualization and courage. The latter is "like a muscle," she told Schurenberg. The more you develop it, the stronger it gets.

2.  Find models and mentors who encourage confidence.

Life and success are much easier if you can find role models to imitate and inspire. Blakely talks about two such mentors that she never actually met (well, not until many years later).

The first of these was a motivational speaker named Wayne Dyer. She discovered his cassette tapes (yes, tapes--this was the 1980s) when she was 16 years old.

"I memorized all 10 tapes front and back," Blakely said. "In high school, nobody wanted to be stuck in my car--'Do not ride home with Sara because she's going to make you listen to that crap.' Then fast forward 15, 20 years, I end up on the cover of Forbes. I I got so many texts from people from Clearwater High: 'Damn, should've listened!'"

The other mentor-slash-model Blakely discusses: Oprah Winfrey.

"I just admire her. I saw her as a woman who took charge of her own life and had almost every single mark against her and still rose above that and found the inner confidence to do that, so I took a lot from that," Blakely said. (Years later, in November 2000, Blakely got a massive boost when Winfrey described Spanx as one of her "favorite things" on her television show.)

3. Embrace what you don't know.

People coming from outside a business or a culture can sometimes offer groundbreaking solutions. Their advantages are that they don't know what they don't know, and that they don't have to unlearn all the groupthink. 

The trick is that that kind of lack of knowledge can easily lead to self-doubt, which is basically the opposite result of the visualization and confidence-building goals Blakely describes. Ultimately, however, Blakely said her amateur status was a major advantage when she launched Spanx, even though she didn't realize it at first.

Specific example: Early on, she struggled to get manufacturers to develop a prototype of her product, until one North Carolina factory owner agreed--and only after he ran her underwear idea by his daughters.

That experience made Blakely realize she had an advantage simply because she was a woman. Most of the business leaders in the women's undergarment industry were men, and probably weren't using the products.

4. Focus on a problem first, and then on a solution.

Blakely preaches the idea of differentiating yourself by focusing on the problem you're solving, not the solution you've come up with.

"I'm always saying sell the problem you're solving, not the what," Blakely said. In her case, that would have been the problem that existing women's underwear didn't make women look good enough--especially in the butt.

This is a very business-focused part of Blakely's advice, and it has changed my thinking in one business I'm personally involved in. But I think it works in all kinds of fields, because it stops you from falling in love with your solution--which can and often will change--and instead keeps you focused on the change you want to make in the world. 

5. Turn disadvantages into advantages.

The fact that Blakely is a self-made billionaire can make it seem that all the things she had to overcome were, well--if not easy, at least not insurmountable. But she's very aware of the persistent male culture of business, and the hurdles that created for her.

Yet she said she was "very determined to stay feminine through the whole journey ...  very interested in seeing how things would turn out if I didn't play by the typical masculine roles [by] operating so much more from intuition, from gut, kindness as the center, giving back, in service of my customers."

Another advantage: Being underestimated.

"It was very difficult for me to get my product even off the ground or get anyone to give me a chance," she said, "but then being underestimated gives you a competitive edge and advantage.

6. Don't marry the wrong person.

Not long ago, I wrote about the advice Supreme Court Justice Ruth Bader Ginsburg offered for young women. One of her points was to make sure you marry the right person. I heard some well-reasoned pushback on that argument--and I think Blakely perhaps puts it a bit better.

The idea isn't that you necessarily have to have a spouse to be successful; it's that marrying the wrong person can easily upend your chances at success.

In Blakely's case, one of the potential impediments was that she had so much more self-made financial success than many of the men she dated. It's unfortunate, but it's a reality that many men seemed to be intimidated by that. Fortunately, she eventually found someone great, got married, and is now the mother of four.

Her husband is entrepreneur Jesse Itzler, whom we last wrote about when he rented Stratton Mountain in Vermont and planned to climb it 17 times in a row. Blakely talks about a moment of truth she faced when she told him over dinner, "I think I make more money than you think I do."

7. Give back--and give it forward.

Throughout her talk and in many other interviews, Blakely talks about her amazement and gratitude that she happened to have been born in the United States, and during a time when women were finally being afforded real professional opportunities.

How does that affect her? She's one of the 158 super-wealthy people to have signed the Giving Pledge, and she told Schurenberg she's especially inspired by the realization that her mother and grandmother didn't have the opportunities she did--simply by virtue of having been born earlier.

"I would watch my mom and feel a sadness for her about her limited options in life and same with my grandmother. I get inspiration from that. I stay very connected to that. It gives me courage," she said, adding later, "I want to give back. It's always been about that for me. How can I elevate, inspire, empower more women?"