You only get one shot when drilling into tile, so you've got to make it count. Mark your spot with painters tape applied in an "X" pattern to keep your drill from slipping and scratching your tile.
YouTuber shaneconlan1 shows off the trick in the video above. Use a carbide-tipped masonry drill bit which will cut through fire-hardened glazed tile and make sure your drill is not set on the hammer drill setting. He also demonstrates the use of a punch or nail to help start the hole, but we'd caution against that as it can cause weak tile to break.
How to Drill a Hole in a Tile [YouTube]