Fast and accurate way to cut plasterboard to match patress boxes - how
do *you* do it?

Is there a definitive method?

Tried a plasterboard saw (slow, not terribly accurate)

Tried a Fein multimaster with a tatty old blade in it (fast, can be
accurate, but too easy to overcut)

With care and patience, any method will be no problem - but I have a
lot of them to do, so it's worthwhile to find the *best* way.

I'd prefer to fix the patress boxes on the studs first, measure the
loose board with reasonable accuracy, take out a core in the board, in
approximately the right place with a holesaw, pull the cables through
the hole, fix the board, then trim the plasterboard to match the
patress box.

However, I could leave the cables loose, fix the board, cut the holes
for the patress boxes (using a template), pull the cables through,
then fix the patress boxes through the holes.

What works best?