Draw the outline for the backsplash onto the wall using a pencil and level. Measure the widest and longest point of the marked area. Use this as the measurement to determine how much tile to purchase. This measurement provides for enough excess tile to allow for breakage.
Cut the backer board to fit the outline on the wall with the table saw. Mark the placement for any pipes or electrical outlets on the board. Cut the openings with a small jigsaw.
Screw the backer board onto the wall using 2-inch screws. Screw every corner into place and add an additional screw every 24 inches along the edges of the board.
Apply a 1/4-inch layer of tile adhesive to the back of one tile using the small trowel. Place the tile into the top left corner of the backsplash. Coat two additional tiles with tile adhesive and place directly below and to the right of the existing tile. Use a 1/4-inch tile spacer between each tile. Use a tile cutter to fit tiles that are too large into place. Glue all of the beveled tile pieces to the wall using this method. Allow the adhesive to set for about 24 hours.
Remove the tile spacers. Fill in the gaps with grout. Allow the grout to dry for 24 hours before allowing water to splash onto the backsplash.