A lot of people think a base coat is unnecessary or prefer to use one product for both the base and topcoat. No bueno! The fact is you can extend the wear of your manicure by at least a couple days just by adding that first proper layer. "It's like primer to foundation," says Miss Pop. "Your natural nail has oils in it that prevent nail polish from adhering well. You need to seal out the oils first with a base coat before you apply a color." She recommends Deborah Lippmann Gel Lab Base Coat ($45 for the set). "It's a splurge, but I get 10 to 12 days of wear with it, and I work with my hands," she explains. Other picks: CND Stickey Base Coat ($9), and Orly Bonder ($10). "Also, topcoat as a base coat doesn't work because it's thicker, it takes longer to dry, and it doesn't have the properties that a base coat does to properly lock out the oils in your natural nails," she adds.