Wouldn't you love to appear 20 pounds thinner without a trip to the gym? Two fashion stylists claim to have cracked the universal fashion code for using clothing proportions to instantly slim down any figure. "This is the biggest secret in fashion," says Ruth Levy, who learned the code while living in Paris. "There is an exact mathematical equation for how to wear every piece of clothing in your closet." Click on the video to learn how to calculate the most flattering placement for hemlines, necklines and sleeve lines, which means a slimmer look could be as easy as a trip to the tailor!

Ruth and her twin sister Sara are also sharing their favorite fashion tips below. And if you have a question, you can talk to them on the message board!

Neckline "The best neckline for all women is a V-neck," Ruth says. "It transforms your upper body from a beer can and into a wine glass! ... We've been amazed. For the years that we've used it, we've not found a single person that it doesn't work on!"

Slim your hips through your sleeves. "Where do sleeves fall? Right at your hip. If you have extra sleeves there, you have more hip!" Sara says, explaining that fitted clothing will always make you look younger and more trim. "This is a really great secret to take away: Extra fabric equals extra girth. You know, you gain a few pounds and you think you're covering it with oversize clothing? But the converse is true. You're just simply adding girth to your figure because nobody knows if that's air or you, and they assume that it's you."

Pant lengths For a sleek look, keep pants long and slim. A longer hemline will give the illusion of a slender figure, because when people look at you their eye has farther to travel to reach the end of the hem. And, if you're trying to look slender avoid wide pants. They always create wide legs.