Beginners learning how to apply liquid eyeliner are almost always guilty of pulling and tugging the eye during application. According to our experts, this is one of the messiest mistakes you can make. "When you pull then release, your eye bounces back and so does your eyeliner," Stewart explains. "This can create bumpiness, texture and the dreaded check mark hanging off the eye."

Instead, you want to let your brush or applicator do the work for you, says Blair. With eyes open and relaxed, anchor your elbow against the mirror in front of you and pivot with your elbow, not your hand, to draw your line in one smooth motion.

"If you're using a gel or cream eyeliner with more viscosity, press your applicator in individual motions down the eyelid," Blair advises. Think of it as baby steps toward a perfect, even line.

When learning how to apply liquid liner like a true pro, it's important not to forget the details. "Liquid eyeliners have different finishes -- glossy, shimmery and matte," explains Stewart. "Ensure that you are purchasing the right one for your look."

Matte and glossy finishes are the most traditional for cat eye effects, she says. (Try NYX Cosmetics Matte Liquid Liner, $6.99). It's also smart to choose a waterproof liner, such as Make Up For Ever Aqua Liner, $23, "to avoid all your hard work transferring into your crease or smudging throughout the day."

Don't be afraid to try a little color, either. Navy eyeliner for brown eyes, eggplant for green or hazel eyes and bronze for blue eyes tend to be the most flattering shades. (Try mark On The Edge Hook Up Liquid Eyeliner, $10).

Learning how to apply liquid eyeliner perfectly every time is practically impossible, and eyeliner mishaps happen even to the pros. Luckily rogue lines and smudges are easy to fix.

Dip the edge of a small square brush, such as M.A.C. 239 Eye Shader Brush, $25, in a silicone-based eye cream (try Olay Regenerist Eye Lifting Serum, $21.99) and do a quick sweep to clean up your liner. The silicone-infused formula will make sure the rest of your makeup won't smudge or change, Blair says. If you end up with an asymmetrical cat eye, you can use the same technique to shape and refine the edges of each wing.