Step 2 : Plan the tile layout on the wall
Make a horizontal and vertical layout line in the center of the wall to help align the tiles. Draw the horizontal line about half way up the wall. To establish the vertical line, measure the width of the wall and mark the center, then draw the line through this point.
You will begin installing tiles at the intersection of these two lines. The best layout has as many full tiles as possible with the border tiles no less that a half a tile wide so some adjustment to these lines may be necessary.
Use a carpenter's level to make sure the layout is level both vertically and horizontally. Then dry fit the first horizontal tile by holding it in place at the intersection. Moving right along the horizontal line mark the location of the edge of the tile on the wall. Then move the other edge of the tile over to this mark. Again mark the edge of the tile on the wall and move the tile right repeating this until you reach the wall. Note how close the last full tile is to the wall. If it is less that a half a tile, shift the vertical layout line to the left a bit.
Use this same procedure to adjust the horizontal layout line. You may have to move the horizontal line up or down to adjust the width of the last tiles. The goal is to avoid cutting narrow border tiles.