A nail file is a paper file that is used to trim the tip of the nail by cutting it. Usually one side is fine and soft (fine sand surface), the other side is thick and hard (coarse sand surface).
The nail file should be firmly grasped by three fingers: thumb, forefinger and middle finger. The hand should be palm-shaped and the fingers should be bent. Dont shake your nails. File the nail tip from right to left or left to right in one direction. When trimming both sides of the nail, keep the same strength from right to center and from left to center. It is best not to file the brittle nails on both sides