The Secret to Looking Slim on the Red Carpet

Designer Mark Zunino has designed for the legendary likes of Sophia Loren, Elizabeth Taylor and Barbra Streisand, and now he's giving ET the secret to looking perfect on the red carpet.

"The key to every gown I do is the inner corset, and these are all custom-made, custom-fit -- I learned this back in the day from Nolan Miller who was a famous Hollywood couturier," he reveals. " ... The importance of it is it's done with a non-woven fabric, so there's no stretch to it. We can pretty much take two to three inches off of anybody's waist by pulling them into one of these."

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Zunino confirms that contrary to what it appears, not every woman in Hollywood naturally has the perfect physique.

"If you look at those actresses, you'll see sort of that severely tapered waist -- it's a very sexy look. Most women naturally don't have that, so it takes a bit of help to get that look and that's what I'm known for pretty much with all my gowns," he admits. " ... Most [Hollywood] women don't [have the perfect body]," he reveals.

But according to the celebrity designer, who aside from his own label designs a wedding dress line for Kleinfeld, you don't have to have a lot of money to look red carpet ready.

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"Pay attention to fit -- you can take something that's really inexpensive and if it's fit well you look like a million bucks," he stresses. "So, I mean that really is the key. You don't have to spend a lot of money on fashion, you just have to have well-fitting clothes."

Check out the video for his advice on how to avoid wardrobe malfunctions, as well as what it's like designing for ET's own Nancy O'Dell!