Katie Holmes wore a Marchesa Notte red lace dress to the designer's fashion show on Feb. 12. Credit: JUSTIN CAMPBELL/startraksphoto.com

As an actress, designer, and single mom, Katie Holmes has mastered the art of looking chic while juggling her busy life.

Her laid-back all-American style always strikes the perfect balance of feminine and sexy -- and Holmes' secret to success just so happens to be an easy one to learn.

"I think you have to know the silhouettes that work for yourself and do things that are comfortable," Holmes, in a red lace Marchesa Notte dress with nude pumps, told Us Weekly at the Marchesa show during Mercedes-Benz Fashion Week on Wednesday, Feb. 12. "I always tend to go plain."

For the Bobbi Brown spokeswoman, 35, that usually translates to dresses with a natural waist, simple necklines, and solid colors. But that doesn't mean the Holmes & Yang designer doesn't take a fashion risk. "If I’m going to do a trend, then I’ll do that trend and pair it with something plain," Tom Cruise's ex-wife told Us. " I don’t do that trend from head to toe." Case in point: For the Donna Karan show, Holmes wore a sexy leather dress with an on-trend sheer skirt.

Also in the front row at the Marchesa show were Anna Kendrick, Sarah Paulson, and Tyra Banks.