If you’ve ever filed your nails in an aggressive back-and-forth motion, this one’s for you…When I think back to my middle school days of sticky, fruit-scented lip gloss and crimped hair, I can’t help but have flashbacks of sawing my nails back and forth with the cheapest, leopard-patterned nail file I could get my hands on. Thanks to my mom’s constructive criticism and a much-needed change in taste since then, I’ve learned to file the right way and to invest in some newer, better nail files. So if your nail filing technique is more middle school than salon level, we’re here to help. We chatted with celebrity manicurist Angel Williams to give us the scoop on the right way you should file your nails to avoid breakage.What is the correct way to file your nails? You should always trim first and use the file for detailing. You should not use a file for shortening your natural nails. Trim with clippers for length, and file for shape. The sawing, back and forth motion is a no no for shaping your nails. You should file in one direction from the side of nail to the center of the nail with short strokes. Then alternate sides. And one to two swipes fully across for finishing the shape. But be mindful not to file the sides too much because the sides of the nails are stress points and if weakened it will cause breakage.Also, hold the file flat up against the nail when filing. If you angle to much it could thin your nail tip.  What’s the deal with files, anyway? Does it matter which one you use?The rule of thumb for files is the higher the grit, the softer the file. So for natural nails a file grit of 240 or higher is best and for very thin weak nails a crystal file is best. Grits that are 180 or lower are intended for enhancements (acrylics and gels).