Like 3_Falls suggestion for the ply template - thanks for the pinning the photo
- will keep note of the various other responses.
I originally started with my laser to align the centre for all the shower outlets to the rough in box and has worked for the ceiling rain shower cutout when I laid the plasterboards, it’s all dead centre to the rough in box which is a start! Might just fork out the cost for the diamond hole saw cutter (will end up installing three of them in my house and maybe I can sell it on afterwards).