This how-to video explains how to use a tile file to remove a sharp edge from a piece of tile. To being you just need to buy a tile file (or a couple if you plan to use it a lot). A tile file would be used if a piece of tile has a sharp edge that you cannot hide in a corner or cover with another piece. To use the tile file simple rub the tile file against the tile like you would a piece of sandpaper on wood. Rub the tile file back and forth until the sharp edge has been smoothed out and then place the tile where you want it.