"Very few people need to apply a full face of foundation—unless you're going to be on camera or it's your wedding day," says Ramy Gafni, a New York makeup artist. But if you do choose to wear it, the best way to find the right color is to swipe a bit of foundation on your jawline. In natural light, the color should disappear. Dot it on your forehead, nose, cheeks and chin, and blend with your fingers or a clean sponge.