What it is: A limited-edition sophisticated nail lacquer with a couture spirit. What it does: This long-wearing, gel-effect nail polish is available in colors to complement Dior's limited-edition Atelier of Dreams lipstick shades. How to use: Start with a thin coat of base coat. Apply an initial, very thin coat of nail polish, starting in the center of the nail then continuing on to the sides. Follow with a second, more generous coat to add depth