Hanging

Two scrap-built T-braces cut to ceiling height minus board thickness that pinch ceiling drywall in place while both hands screw.

Putty pads on the boxes, mineral wool in the cavity, and double 5/8 drywall with damping compound between — mass plus damping plus sealed flanking paths.

Raising and holding a wall sheet in position by yourself while both hands stay free to fasten it.

Riding a tape measure along a sheet's edge to score or mark a parallel line without a chalk line or straightedge.

Getting a ceiling sheet up and held in place without a lift.