Thanks Andy, practice makes perfect (or near enough to perfect). I liked the way you did yours - they came up alright!
I've been practising with the forstener bit but it's still a bit dodgy. My thinking though is that close enough is ok - the smaller holes just have to be close but not perfect since they're covered by the bridge anyway. As for the rear ones, as long as the ferrule holes are straight then it should be ok, right?