Place a piece of duct tape over the tile section you want to drill.
Measure the distance between the two holes you want to drill. Make a mark on the duct tape to indicate where you will drill the holes.
Equip a handheld drill with a carbide or diamond-tipped drill bit. Drill the holes at a right angle. Set the drill speed at 100 to 200 rpm then press the drill tip into the tile lightly. Occasionally spray the bit with water to keep it cool.