Jamie Mizrahi

Plus, Net-A-Porter invests in sneakers.

Who said you can't wear black and brown together?

The woman behind the fashions of Katy Perry, Riley Keough, Suki Waterhouse and Nicole Richie is applying her styling know-how to the California brand.

Hint: don't expect it to be glamorous. At least, not always.

Here, she shares wisdom she learned by climbing the industry ranks to build a client list that includes today's most promising up-and-coming talents, as well as bona fide icons like Katy Perry and Britney Spears.