Mix dry plaster with water in a trough or bucket to form a thick paste-like consistency. Use a power drill with a mixer bit to blend the dry plaster mix thoroughly.
Dip a trowel into the wet plaster and spread it from the trowel over the hawk, keeping a 1-inch distance from the edge of the hawk.
Add more wet plaster to the surface of the hawk, building it up to 2 to 3 inches. Plaster with correct consistency will not run off the sides of the hawk.
Climb the ladder or scaffold to reach the ceiling easily. Hold the hawk in front of you with your less dominant hand. Bend your elbow to bring the hawk to just below shoulder level.
Pick up plaster from the hawk with a trowel and apply it to the ceiling. If you picked up too much plaster, return the plaster to the hawk. Keep the hawk under the area you're plastering to catch drips.