Drilling through ceramic tile is a risky procedure, as the tile’s fragility makes it prone to cracking and breaking. You must use patience and acquire the correct tools to get the job done.
Clean the tile's surface. A clean tile ensures that the surface is level. Examining a clean tile also allows you to determine that there are no cracks that could make drilling a tile problematic.
Protect yourself. Put on safety glasses. Ideally, the tile should not chip or break; but in the event that it does, your eyes should be protected.
Insert a carbide-tipped masonry bit into a battery powered or corded drill. Carbide material drill bits are sharp and durable because carbide is extremely hard. Carbide alone can be rather expensive, so many bits are a combination of carbide and steel. If your hole is larger than a 1/4 inch, use a small carbide drill bit to make a pilot hole and another one to drill the hole to the size you need. Without the pilot hole, you bear a much greater risk of cracking the tile.
Penetrate the surface of the tile. Ceramic tiles, which are common in kitchens and bathrooms, often have a hard, glazed surface to protect the tile from damage. A drill bit will skip and jump around on the smooth surface which can add unwanted scratches. To avoid this, try the following: Make an "X" shape using masking tape that crosses over the spot where you want the hole. The masking tape helps by giving the drill bit some traction. The tape also prevents the outer rim of the hole from chipping. Penetrate the glazed surface. If you are drilling a pilot hole, use the smaller carbide drill bit. Once you have broken through, stop the drill before continuing to the next step.
Lubricate the bit to keep the drill from overheating and help control dust. Fill a glass with water and keep it available. Using one hand or the assistance of a helper, pour a consistent trickle of water on the rotating bit. Put a towel underneath the hole to soak up the water.
Drill through the tile. Set your drill to a low speed and apply modest pressure to the surface. Allow the drill to work slowly rather than push hard and crack the tile. Applying too much pressure can cause the tile to blow out and crack on the backside, creating a weak spot in the tile and often a much larger hole than originally intended.
Penetrate the backing board. You can switch back to a regular drill bit for this process if you prefer. Continue to drill slowly and be patient, because it is just as important to maintain the wood or drywall behind the tile. Damaging the backing board can make it difficult to use anchors for hanging a towel rod, screw or whatever you're planning to use the hole for.