Color. It can be hard to incorporate into any makeup palette if you aren't careful. The rule of thumb for adding a dramatic tint is: all things in moderation. Take Demi Lovato's example and select one bright hue as an accent. She decided to go with a pop of blue at the X Factor season finale last night. To get a similar look, apply a pigmented liner like Yves Saint Laurent Waterproof Eye Pencil in Azure Blue ($29) on two-thirds of the bottom lid, leaving the inner corners clear. Give the shape a cat-eye flick for added drama. Go for typical black eyeliner on the top lid to keep the look from getting too overwhelming. Finally, keep the remainder of the face in neutral hues. A colorful eyeliner is really the only thing you need to update your everyday makeup look for a holiday party.