Stila Cosmetics is one of those brands you stumble upon at Sephora and become instantly devoted to. They also make your favorite eyeliner by a very wide margin. And if you need to stock up on said eyeliner, Stila is running a buy one, get one free sale on the uber-popular Stay All Day eyeliner. Just add two to your cart, use the code FRIEND, and get your supply of black ink.