Shapes are important, but not as important as you would think. The nail file can come in quite a few different shapes like diamond, banana, straight wide, straight slim, half-moon and much more. Everyone has a certain preference, but at the end of the day they are all nail files and they will work the same way. It will still get the job done the same way. Now, it should be noted a lot of professionals in the industry swear by the half-moon shape because you are less likely to cut yourself on it and damage your cuticle or the areas by the cuticle. However, it’s really up to you. Try them all out and see which one you prefer.