Kardashian loves having her nails done at the salon, but always does the filing herself. "I'm OCD," she says. "[My nails] have to be perfectly square. I carry a file with me everywhere I go. I get anxiety when I get my nails done if it's not the person I use all the time, because I don't want to offend them when I ask to file my own nails!" Keeping an emery board in your bag will allow you to fix snags and shaping. Just use it right: File in one direction to prevent breakage. And "don't shape the sides of the nails unless they're at least an eighth of an inch beyond your fingertip," says manicurist Deborah Lippmann. "Otherwise, it could weaken them."