Founder, Mally Beauty
The celebrity makeup artist launched her own eponymous beauty line in 2004.
Biggest mistake: Not being me
"When I was starting out, I wore tons of makeup, short skirts, and high heels. Once, a famous hairdresser pulled me aside at a shoot and told me that everyone was laughing at me. I went home and cried. The next day I came back wearing jeans and no makeup. But I felt like I wasn't doing my thing. That's when I said, 'Fuck it. I have to be who I am.' I probably looked like RuPaul at some shoots. But no matter what, you have to stay true to who you are."
Creator of The Guild
The TV actress writes, produces, and stars in the monster-hit Web series The Guild.
Biggest hurdle: Getting off my ass
"I had these ideas and characters in my head. But I wasn't brave enough, didn't have the self-discipline to sit down and put them on paper. It seemed so scary to me that I might fail, that I wouldn't be any good at writing or that I'd waste my time. So I finally laid down the law and gave myself a deadline. I tried to write one hour a day, and yes, I fell off the wagon a lot. But that was a huge step for me—I wasn't going to indulge myself anymore."
Thiers runs the nation's largest online job site for nannies and babysitters.
Biggest regret: Not delegating more
"When I first started the company, I did everything—customer service, PR, marketing, hiring. It was hard to let go. It got to the point where I was literally taking walks around the block just to get a moment's peace to think. If you don't delegate, you become the only person everyone goes to for information."