Next week marks the premier of AJ Cutler’s The September Issue, a documentary detailing the “behind the scenes” at Vogue and editrix Anna Wintour’s leadership.

Sienna Miller, cover girl of the 2007 issue, also appeared at the movie premier held in New York City on August 19th. She sported the “disheveled glam look” that’s oh so popular today.

Sienna Miller in The September Issue

To get the celeb red carpet look, celebrity hair stylist Kevin Mancuso (who styled Miller for the premiere) gives us the follow tips:

The Look: Hair is worn down with loose, bohemian-chic waves

Enhance your natural texture by applying a volumizing or curling mousse, such as Nexxus Mousse Plus or Nexxus Gorgeous Curls, at the root and spreading to the ends.

Sienna Miller on the September 2007 cover of Vogue

Flip head over and blow hair around while massaging the roots with your finger tips. This will help build texture into the style.

Style: Once dry, flip head back up and brush out to remove major tangles.

Create a center part and smooth out the top 1/3 of hair with fingers.

Tilt head to side and taking random sections of hair drag medium curling iron down to ends. This action helps to create long, loose, uneven waves. Let the natural fluff come through for an of-the-moment look.

Finish:

Finish look with a misting of a light hold hairspray. We love L’Oreal’s Elnett Hairspray that gives you impeccable hold without being tacky.

It will help maintain the look on and off the red carpet, while allowing the movement of the style to shine through.

– By Charu Suri