Lip liner has acquired a bad rap over the years, and for good reason: Use too dark of a color and you'll look dated (enter ‘90s grunge flashbacks). Draw too far outside of your natural lip line and you’ll look about as natural as Kylie Jenner. When used correctly, though, a lip pencil can help you achieve the subtle fullness that makes your natural lips stand out that much more. “It adds definition by creating precise lines, works as primer to prevent feathering and creates the illusion of a plumper pout,” explains Los Angeles-based celebrity makeup artist Kayleen McAdams. Here, she shares the top mistakes liner-lovers make, plus her secrets for getting it right, every time.

Mistake: Choosing the wrong hue

To achieve the desired look, you have to choose your liner wisely. If you're going for the illusion of bigger lips, choose a liner that is one shade darker than your lipstick. Blessed with a naturally plump kisser? Opt for a matching color. McAdams recommends MAC Cosmetics Lip Pencils ($17; nordstrom.com): “The shade range is wide and they have unbeatable staying power.”

Mistake: Lining lips before lipstick

Instead, apply a coat of lipstick first. “The color will help make the rim of your mouth more apparent, so you can go in and build up or define uneven edges,” McAdams says.

RELATED: 8 Best Overnight Beauty Products to Wake Up Gorgeous

Mistake: Working too fast

"Don't try and conquer the entire circumference of your mouth in one swoop,” McAdams says. Instead, she suggests using small, light-handed strokes. Start by defining the center of lips—cupid’s bow and bottom—then carefully work your way out toward the corners.

Mistake: Not blending enough

The last thing you want to see is a harsh line, especially as your lip color fades throughout the day. Buff the edges with a Q-tip to soften the look of the liner, then swipe on a final coat of lipstick and smooch lips together to blend.

Mistake: Skipping shine

For an extra boost, dab a creamy highlighter on the Cupid’s bow and the center of the bottom lip. “The subtle sheen will reflect light, making lips look shapely,” says McAdams. Try NARS Shadow Stick in Goddess ($28; sephora.com). “It's meant for eyes, but it also works beautifully on the lips,” she confides.

RELATED: 9 Glam Gifts for Beauty Addicts