Measure up from the tub deck the height of the tile sheets-12 inches plus 1/8" to allow for a grout line along the tub deck (Image 1). Draw a level guideline for the tile with the two foot level (Image 2).
Since the tile is going on regular drywall, not cement board, use pre-mixed ceramic tile adhesive, or mastic, instead of thinset. The mastic doesn't set immediately so its easier to work with. Spread it on the wall with the 3/16th V-notch trowel (Image 1). The top of the tile follows the level line all the way across for a uniform look (Image 2). This leaves varied spaces on the bottom, so use plastic shims to make up space. Line up the next sheet so it fits perfectly, leaving a space between the two for a grout line.
Now that you've reached the corner, measure out to determine the size of the sheet.Use the measurement to cut the tile sheet to size. Lay the tile mesh-side up on a piece of cardboard. Instead of running the mesh sheet through the tile saw to make the straight line, simply use a utility knife on the mesh, following the line of the tile. This will leave small spaces between the tile and the corner, which will be filled in with the next piece. For the corner piece, set a full sheet matching it up with the sheet from the other side. Around the window, use the utility knife to cut the mesh as close to the window as possible. The spaces will be filled in later with individual tiles cut with a wet saw.