Marking and cutting.
It depends on the size of the tile. We mark the surface to determine the right amount of tile and its shape with dimensions. During the marking, look at the size of the seam, it is on average from 2 to 4 mm. In the absence of experience, the cut is done carefully so as not to damage the tile. To compensate for inaccuracies when cutting the tile, you need to purchase it with a «margin».