Hold the nail shaper at a 45 degree angle under yor nail edge. Begin with the fine side to smooth off ragged edge and use the extra fine side for a extra finer smooth edges. This nail shaper is water resistant. You could use it wet or dry. To prevent nails from peeling, file with dry nails. File in one direction to prevent splitting.
Care: Use bristle brush to remove residue. Do not leave the nail shaper in water.