Carey Mulligan Wall Streetpremiere

Carey Mulligan at the "Wall Street: Money Never Sleeps" premiere in New York City. Photo: Andrew H. Walker, Getty Images

What's it like seeing your face on the front of Vogue magazine? "Amazing, surreal, and I'm very grateful," October cover girl Carey Mulligan, wearing a Nina Ricci dress, told reporters at the Sept. 20 "Wall Street: Money Never Sleeps" premiere In New York City.

The beautiful 25-year-old certainly belongs on the fashion bible, according to co-star/boyfriend Shia LaBeouf.

"Carey knows a lot about fashion. I'll be honest with you," he gushed to StyleList.

As for her character's outfits, the actor said, "I honestly think Winnie's style is spot on. I'm not a fashion guy, but I like the way she looks in the movie."

Besides having a stylish body, Mulligan also has an impressive body of work, according to the smitten actor, "She is an incredible actress and powerful and incapable of having a false moment," said LaBeouf. "She's probably the best actress of her generation."

"Wall Street" costume designer Ellen Mirojnick shared with StyleList her secret to styling Mulligan's unaffected character.

"Winnie is not a fashionista. J.Crew is mixed with Alaia, Prada is mixed with Club Monaco. She wears it with quite the right amount of elegance and ease. Nothing is fussed over."

Mulligan was generally quite involved in the styling process, Mirojnick added. "We worked very, very closely together. Everything that you see her in, she loves."

While Mulligan was somewhat indifferent about the large, round-cut Bulgari diamond engagement ring she sports on screen, she was definitely quite vocal about another item she wore. "The vintage Oscar de la Renta gown," revealed Mirojnick, adding that the actress exclaimed, "I have to wear it!"

When it comes to her off-screen style, Carey Mulligan doesn't let anyone dictate her look... Not even Vogue editor Anna Wintour.