Straight teeth might get you hired, and dark eyes might tempt someone to tell you all their secrets; but out of all our body parts, research shows that full lips are the key to a woman's sensuality.

According to a study out of Manchester University, the average man will spend the first five or six seconds after meeting you fixated on your mouth -- that's twice the time he'll spend on your eyes or hair. Lead researcher Dr. Geoff Beattie, PhD, says, "Lips represent one of the most sensual aspects of a woman's body and play a critical role in human sexual attraction." His study shows that women wearing lipstick "secure significantly greater levels of attraction" than those without. But full, pouty, red lips are the ideal combination.

However, we aren't all blessed with an Angelina Jolie sized pout or the Kylie Jenner sized budget for lip injections. Still, there is hope. We spoke to a group of celebrity makeup artists to get the professional scoop on how to make your lips bigger using sneaky makeup tricks only. These quick and inexpensive hacks are guaranteed to earn you at least a seven-second stare.

The first step to bigger, sexier lips is making sure they are properly exfoliated and moisturized. But for an extra boost, trade your regular lip scrub for a naturally plumping, cinnamon-based concoction.

Spicy cinnamon mildly irritates the lips, causing them to swell temporarily (in a good way, trust us). Blend two tablespoons of coconut oil, a tablespoon of sugar and two drops of cinnamon essential oil (or a tablespoon of ground cinnamon), then scrub. Follow up with a thin layer of Aquaphor lip repair, $4.99, and behold your naturally bigger lips.

To make your lips look bigger, before applying any lip liner or color, start by redefining the boundaries of your lips. "You can use foundation to fake a larger canvas," says California makeup artist Ana Miriam of Classic Glamour Dolls. "Pat foundation onto your lips, spreading it a little over your lip line." Not only does this make your lipstick apply closer to the color in the tube, it also allows you to extend slightly outside the lip line, making your lips look larger without an obvious change in color from lip to skin.

When choosing a lip color, keep it light to give the illusion of bigger lips, advises celebrity makeup artist and founder of GlossiGirl Cosmetics Stephen Dimmick. "Darker colors only highlight the natural size of your lips," he says. "So if you don't already have full lips, a dark color will accentuate the thinness."

"Instead, choose a shade similar to the color your lips blush naturally," says makeup artist Liz Washer. That means roses, berries and caramels, depending on your natural skin tone. (Try: Yves Saint Laurent Beauty Rouge Pur Couture Vernis a Levres Glossy Stain in Rose Vinyl, $36, or Bobbi Brown Sheer Lip Color in Natural Pink, $27).

If you're going for fuller lips, liner can be your best friend -- but aim for subtlety in both color and technique. "Over-lining the lips with a dark shade can look clownish," Washer says.

Instead, for bigger-looking lips, choose a lip pencil close to your natural lip shade, and line along the very edge of your natural lip line with short, sketching motions. You want to emphasize the Cupid's Bow (that's the dip in the center of your top lip), as well as the fullest part of your bottom lip, all the way to the outer edges (which often get lost). "Finish by filling in the entire lip with pencil and applying lipstick on top, blotting for a long-lasting finish," Washer says.

If you want to over-line for extra fullness, use your pencil to build color right outside your natural lip line in the center of the bottom lip and on either side of the Cupid's bow. "Don't over-line around the entire perimeter of the mouth, as it can begin to look fake," says Washer. (Try NYX Cosmetics Retractable Lip Liner in Soft Pink, $4.49, or Make Up For Ever Aqua Lip Waterproof Lipliner Pencil in Rosewood 2C, $19).