You shouldn t need to cut the tile unless it is an end tile that completes the row.
Tiling a bathroom wall with a window.
Use bullnose tiles to round off the edges of the window frame and tile the wall first.
Mark the tile where it overlaps the full sized tile and number it on the back side.
Line up a tile with the edge of the window and protruding out over the full sized tiles on the wall.
That way you can make sure the grout lines of the recess are on the same plane as the wall.
In order to tile around a window you have to spread thin set on the wall by using a notched trowel.
When tiling bathtubs backsplashes and other areas that use limited quantities of tile buy the best quality tile you can afford.
Anytime the tile meets the window itself i use a sealant.
You can expect to spend about four to five hours tiling a standard 36x40 inch double hung window.
In a bathtub area the cost difference between using this cheap bland 0 69 tile and a better quality 4 75 tile is negligible.
Then measure around the window as to cut the tiles with a score and snap cutter or a wet saw to fit into location.
This will allow you to leave room for the adhesive that will secure your tiles to the wall.
With the sill in i can tile the sides of the window.