Ceramic tiles can shatter easily, and drilling a hole into them is tricky. It's important to use the correct type of drill bit at the right speed and with very little pressure. Regular drill bits can make a rough and ugly hole, and they may cause the tile to crack. Tile bits with ground tungsten carbide or diamond tips are the best for this purpose. They are both designed to drill into hard surfaces, and both of them puncture the tile with a cone-shaped hole. Drill bits with carbide tips need to be used at low speed, and diamond tips need to be cooled to prevent the tips from heating up, which can cause the tile to shatter. Drill bits with diamond tips are more expensive but very durable, and they don't burn out as easily as other bits.
Drilling through ceramic tile requires patience and time; keep a slow steady hand on the drill to prevent damage to the tile.