Whether you use it to cover undereye circles, conceal broken capillaries or other red areas, or to cover blemishes, concealer might just be the most useful tool in your cosmetic arsenal. Some tried-and-true techniques can ensure that you do a great job covering those problem areas. First, start with clean, moisturized skin. Dry skin can give the makeup a cakey look and allow it to settle into fine lines. Prime areas that need concealer with either a primer made for the face or eyes, if it's to be used around the eyes. That skin is the thinnest on your body, so it tends to show shadows, veins and other imperfections. It also requires a light touch to keep from bruising it - always use your ring or pinky fingertip to touch skin around the eyes. Some experts recommend going a shade or two lighter than your skin on undereye circles, but this tactic may make that skin too light, calling attention to the very spot you want to conceal.