[quote author=Little_Miss_DIY link=1081474968/0#0 date=1081474968]Should I use the grouting as a guide line to drill into? [/quote]
No. If you attempt to drill in the grout lines you are likely to cause a situation where the drill bit will snatch against the edge of a tile, and that could cause the tile to get broken.
Drill holes in ceramic tiles somewhere away from the tile edge where possible.
You need to buy a special ceramic tile bit, which is a bit like a pointy little spear - this has a very sharp cutting angle (unlike regular drill bits which are a shallow cutting angle). The sharp point on the bit helps it to hold to a given point rather than slip across the surface of the tile. You can put a piece of tape on the tile to help here, though I haven't found it necessary myself.
Drill slowly until the tile bit is thru the tile, then switch to a regular masonry bit to dig the hole for the rawlplug.
Quote:I'll be absolutely gutted if I damage the tiles
You will have to damage the tile to put a hole into it. But I know what you mean
Andrew