Clear out the room by taking out all furniture to give you an open space in which to work. Spread drop cloths over the floor to catch any dripping paint.
Dust the ceiling with a wall and ceiling duster to remove all the dust from the ceiling.
Pour ceiling paint into a paint tray and connect an extension handle to a paint roller. Place the roller in the paint tray and roll it until it's coated with paint.
Begin in the corner opposite from the entryway and roll the paint onto the ceiling with the roller, going in one consistent direction from the corner to the entryway. Allow the ceiling paint to dry for 3 to 4 hours.
Apply a second coat of ceiling paint to the ceiling going in the same direction, starting in the corner and working your way to the entryway. Allow the second coat to dry, then remove the drop cloths and replace the furniture to finish.