If the term "body contouring" makes you think of muscly body builders and crop-top-wearing pop singers, your mind is about to be blown.

Every time you get a good professional spray tan, they do some subtle contouring -- whether you realize it or not. That's because contouring takes a fake tan from flat to natural looking and makes your legs look half the size.

How exactly? It's all about optical illusions. "You don't want to look like you're contoured, just faint definition, " says Tamar Vezirian, owner of Gotham Glow in New York City. "It should be faded out so you almost can't see it -- you'll just seem more toned than usual."

Excited to try it? Read on for body contouring tips so you can get started today.