Find a fairly soft surface, have them take off their shoes, and place a pencil or piece of tape on the ground. (sportstarsmag.com)
Fold them into place, and then put a few pieces of tape over the rogue seam to hold the edges together (on the inside of your garment, of course). (theeverygirl.com)
Just line your lips with pieces of tape before applying your lip color and you'll never have to worry about messing up your lip shape again! (seventeen.com)