Move as much furniture out of the room as possible. Lay tarps over the floors and drop cloths over the remaining furniture. Take pictures off the walls and remove window treatment. Cover hanging light fixtures with heavyweight paper secured with masking tape.
Wear safety glasses. Examine the ceiling for popped nails. Climb a ladder and drive in popped nails with a hammer.
Add 1 teaspoon of grease-fighting dish soap into 1 gallon of water. Submerge a sponge mop into the water and squeeze out the excess water. Place the mop against the ceiling, beginning in a corner, and scrub the ceiling to remove grease, oils and surface dirt.
Equip a power drill with a paddle mixer attachment.
Scoop half of the contents of a 5-pound bucket of drywall joint compound into a separate bucket with a drywall joint knife. Add 1 quart of water. Place the paddle mixer into the joint compound and water and blend it to a milkshake-like consistency.
Pick up the joint compound with a joint knife and place it on a hawk.
Climb a stepladder or set up scaffolding to gain access to the ceiling beginning in a corner of the room.
Spread a 1/4-inch layer of joint compound over a 3- by 3-foot section of the ceiling.
Hold a thin putty knife at a low angle to the ceiling with the blade facing to the left. Press the knife into the joint compound 1/8-inch deep. Moving only your wrist, sweep the knife in an arc, pulling it through the wet compound and end when the knife's blade faces to the right.
Place the knife facing to the left and overlapping the first arc by one-third. Sweep the knife through the wet joint compound and stop when the blade faces to the right.
Continue to overlap arcs until scallops cover the 3-by-3-foot section. Apply a 1/4-inch thick layer of joint compound over the next section of the ceiling to touch the first section. Repeat the process until the scalloped texture covers the entire ceiling.