There's nothing new about fashionable women borrowing from men's style; just think of Marlene Dietrich, Brigitte Bardot, or Diane Keaton.
A sure way to claim a bit of cool in Hollywood - if you're an actress, at least - is to announce you don't have a stylist. Some of the most consistently elegant, inimitable women on the red carpet, like Marion Cotillard, Blake Lively, and Diane Kruger, say they go at it alone.
In terms of its endorphin-boosting potential, a good hair day is on par with a good workout.