Perseverance is the key to starting a successful business.

My saddlebags are why Spanx exist! Now that I have a baby I also have a muffin top.

I'm obsessed with the customer. I am the customer. I really don't think you can go wrong if you don't take your eye off of that. Serving the customer. How does she feel? I feel like the fashion industry has cared a lot about how we look but not about how we feel.

Everything about my journey to get Spanx off the ground entailed me having to be a salesperson - from going to the hosiery mills to get a prototype made to calling Saks Fifth Avenue and Neiman Marcus. I had to position myself to get five minutes in the door with buyers.

When I was a child, my father used to encourage my brother and me to fail. At the dinner table, instead of asking about the best part of our day, he would ask us what we failed at that week. If we didn't have something to tell him, he would be disappointed. When we shared whatever failure we'd endured, he'd high-five us and say, 'Way to go!' The gift my father gave us by doing this was redefining what failure truly meant.

Eminem's 'Lose Yourself' is my go-to song to pump myself up if I'm having a tough time or if I get really nervous right before a speech.

If somebody can do something 80 percent as good as you think you would have done it yourself, then you've got to let it go.