To safely and accurately drill a hole through a tile I just drill a hole in a piece of 6mm MDF or Hardibacker first with whatever size bit I'm about to use.
Then place that on top of the tile (with the pre drilled hole over my intended hole in the tile), then fill the cavity with water, place one foot either side of the hole and usin the board as a template drill through!
Using this method the drill bit will not wander, which means u can also drill right up to the edge of a tile and it not break out!
I also find standing over the tile enables you to have total control of the drill and keep it perpendicular to the tile.
I always use my large variable speed SDS drill for drilling tiles, it has masses of grunt, the bits don't snag and it's a comfortable height to work with, rather than a combi let's say.
Simple but effective.