Click clacking on keys of all sizes spells doom for your nails. Make them unbreakable with routine maintenance: Keep nails at a manageable length (just slightly past the nail bed). Never file after soaking: water causes nails to expand, which weakens them. Whether you polish or not, protect nails with a treatment product. "If you leave them without any coating, they're going to break", says Donna Perillo, owner of Sweet Lily Nail Spa in New York City, who suggests using Qtica Nail Growth Stimulator, $12 as a base cost. Also, swipe on a clear top coat every few days to protect against wear and tear (and make your manicure last longer).