Measure and cut drywall sheets for the ceiling, using a tape measure and a drywall saw. Cover the ceilings with drywall before hanging it on the walls. Install the first sheet in the corner, flush against the wall and perpendicular to supporting beams or joists. Secure drywall sheets in place with drywall screws. This is a two-person job; one person stands on a ladder holding up the sheet while the other fastens it with screws.
Continue covering the ceiling with drywall sheets. Cut out a circular opening around ceiling light fixtures, using a rotary cutting tool. Secure each sheet with screws.
Mark wall stud positions on the attached ceiling sheets. Install the first sheet on the wall in the corner. Align it with the studs and fit it tightly against the ceiling sheet, so that one edge meets the ceiling while the other meets the adjacent wall. Secure the sheet with screws.
Continue covering the walls with drywall sheets. Measure and cut around window and door openings with a tape measure and a drywall saw. Secure each sheet with screws.
Prepare the room for drywall finishing after the wall sheets have been installed. Drive screw heads below the surface of the drywall sheets but not too deep. Sweep the floor to eliminate debris.