Combine glitter in the color of your choice with clear-coat paint in a 5-gallon bucket, using a wooden stir stick. Use a ratio of three parts clear coat to one part glitter to ensure that your ceiling will sparkle cleanly when light hits the surface. Scrape the sides of the pail with the stirrer as you mix to keep the glitter from clumping along the sides.
Climb a ladder, and mask off the edges of the walls adjacent to the ceiling, using masking tape. Remove furniture from the room, and then cover the floor and any remaining items with drop cloths.
Cut in the edges of the ceiling with a paintbrush. Apply the clear coat along the edges and corners of the ceiling with a paintbrush, covering an area of about 4 inches from the edge of the ceiling inward.
Place a paint roller screen into the bucket to remove excess paint from your roller. Switch to a paint roller attached to a pole extension, and then apply the clear coat evenly to the rest of your ceiling. Begin at the edges of the ceiling, and then work across the ceiling, applying the clear-coat in long broad strokes of the roller. Start each roller stroke in an area already wet with the clear coat, and use a back and forth motion to spread the coat, overlapping each forward stroke with a backward one. Overlap the edges of each applied stroke by one inch, as well. Allow the clear coat to dry overnight before you remove the drop cloths and masking tape.