If the wall is really large i use a square to keep the corners lined up.
How to lay tile diagonally wall.
There are only two ways to handle an inside corner with diagonal tiles.
Using a wet saw cut one tile into a triangle diagonally from opposite tip to opposite tip.
While a diagonal pattern might seem logical if you are using big tiles for an expansive space such as a large kitchen or great room floor many people worry that diagonal tiles can look too busy in a smaller bathroom and if you are a diyer planning to install the tiles yourself you might worry that.
Then every subsequent row is a process of draping over the pyramid back and forth.
If you are laying the diagonal tiles over the entire backsplas simply drawing a chalk line from one corner to the opposite will not work.
For the tiles near the center line up the two sides of the tiles with the diagonal lines and the opposing corners of the tile with the straight.
Homeowners often shy away from diagonal tile layouts also called bias layouts in a bathroom.
Dry fit a row of tiles along each diagonal line.
This is a fold.
Install tiles one through four as directed.
If it seems complicated try this.
Because tile laid on a diagonal has half tiles or pieces of cut tile along each edge of the installation a lot more tile is required to complete the job.
Diagonal tile installations draw the eye out to the sides of the installation visually widening and enlarging the space.
Lay half of first tile with cut side facing 90 degree corner and tips almost touching walls at a 45 degree angle.
Lay out tiles in a dry run to make sure they fit.
Start in a 90 degree corner.