The only thing worth sawing to and 'fro is firewood. This kind of motion
causes even the strongest nails to strip away, leaving you vulnerable
to breaks, peels, and unsightly edges. If you must file, go with a
gentle one 180 grit or less. But if your nails are on the softer side
(like mine!), use the end of a soft buffer to gently shape your nails
into a cute little curve.