Turn on a stud finder and place it flat up against the tile back splash. Move it to the left or right until it blinks or lights up, meaning you have located a wall stud. Mark the location with a pencil. Since nails have no way to cling to drywall or backerboard, which is behind the tile, you must insert it into a wooden stud for stability.
Tear off two 1- or 2-inch-long pieces of masking tape and place them in an X design on top of the pencil mark. The tape prevents the drill bit from slipping on the tile's slick surface.
Install a carbide-tipped masonry bit into a drill and place the bit on the center of the X. Squeeze the trigger on the drill and hold it steady until it breaks through the tile and the thinset or backerboard, which is typically behind tile.
Insert the nail into the hole and hammer it through the wooden wall stud until it is secure and at the proper depth for hanging.