Sand the joints on the drywall to remove any imperfections in the dried joint compound. Use a round sander or a sanding sponge to create the smoothest surface.
Mix powdered drywall mud with water in a 5-gallon bucket, using a stirring bit attached to an electric drill. Add water until the mud is as thick as pancake batter.
Dip a paint roller in the mud, scraping the excess off on the bucket rim. Roll the mud on the wall or ceiling, beginning in one corner and rolling in one direction. Continue to coat the ceiling in mud, adding more mud to the roller as necessary, until the entire surface has a thin coat.
Roll the roller in the opposite direction, smoothing out the mud so you have as flat a surface as possible.
Attach the stomp brush to a pole if you are texturing the ceiling. Roll a thin coat of mud over the bristle of the brush using the paint roller.
Push the brush into the ceiling, using a straight up stomping motion. Pull the brush down, spin it a half turn, then stomp it against the ceiling next to the first stomp. Continue turning and stomping moving left to right across the ceiling. Overlap each new row slightly so there is no space between the rows of stomp pattern.