Sand before you assemble. Automate the sanding as much as possible eg. spindle sanders, belt sanders etc. Try and plan your work so that “construction sanding” as Jim put it, is a minimum or use hand tools for shaping, leveling.
I don’t mind finish sanding when I can use my ROS, but I hate sanding by hand, the dust gets everywhere and I end up coughing for days after.

Rob, Sault Ste. Marie, Ontario