Set the First Row of Tiles
Scrape the wall with a putty knife to be sure you have a smooth, even surface to work with. If the tile runs behind the refrigerator, start at the opposite end with a full tile in the corner.
Set the first row of tiles so they will run about 6" beyond the edge of the refrigerator. Use tile spacers to ensure even spacing.
Spread the mastic with a 3/16" V-notched trowel held at a 45-degree angle. The grooves allow for air to get under the tile and harden the mastic.