If you're one to whip out a dark red or purple, but still want a plump-looking pout, there's a way to work around the rules. To keep your lips looking full, "don't take a dark color all the way out to the outer corners of your mouth," says Dimmick. "If we shorten the width of the mouth, it will give the slight illusion that your lips are vertically fuller."

Instantly amplify your lips by highlighting the Cupid's Bow. "This is an easy way to make your lips pop," says Dimmick. Before applying liner or lipstick, use a lip brush (or the tip of your finger) to dab a shimmery product, such as Nars Illuminator in Copacabana, $30, in the center V of your top lip.

"My No. 1 tip for making lips appear full is to use a sheer smear of concealer around the edge of your lips," says Dimmick. You can do this either as a finishing touch to clean up your lip color, making it look more graphic and precise, or at the beginning, before going in with your pencil. "That way, you can define the lips without using a heavy liner," Dimmick says.

Either way, dip a concealer brush in Laura Mercier Secret Camouflage, $34, and lightly sketch around the edge of your lip line for both highlight and definition.