cutting holes in floor tiles for WC anchor bolts

[jacko5]

Hi all, progressing from self level I am now well on the way to tiling my bathroom floor. Got a good deal from a guy who was emigrating, on E bay, for a Plasplugs Compact wet cutter but also bought a cheap manual cutter that was useless on floor tiles. In the end decided to splash out on a Rubi (no not a curry), the cheapest one they do, at £44 the 40 Pocket, fold up jobbie. This piece of kit is brilliant.
Now to my question, I also bought a diamond cutting set as when I put the loo back, I have to rawl bolt its fixings to the floor. Of course to do this I have to drill clearance holes through the tile for the bolt heads and spanner. Now marking out where these go is a bit fiddly as you have to mark out 2 plastic slanted brackets which sit tight inside the porcelain base. These have multiple holes in so you can locate screws from the side. So, should I drill the tiles in situ after cementing in, or try and drill the tile first ? and hope I can measure accurately enough.

[darrenba]

You drill the holes after the tiles have been laid