Measure the length and width of your bed. Add 3 inches to each of these measurements. Cut your plywood into a rectangle equal to those adjusted measurements.
Stand on a step-ladder to measure the length from the ceiling to the floor. Add 5 inches to this length. Unroll the upholstery fabric face down your flat work surface. Cut two panels of fabric. The long sides should equal the distance from the ceiling to the floor plus 5 inches. The shorter sides should equal the length of the bed. Cut two more panels of fabric. The long sides should be the same length as the previously cut panels. The shorter sides should equal width of the bed. Place the panels to the side.
Spray the front of the plywood board with spray adhesive. Unroll batting on the work surface. Place the board, adhesive-side down, on the center of the batting. Wrap the batting around to the back of the plywood board. Pull taunt and secure by stapling around the edges of the plywood board.
Place the upholstery square face down on the work surface. Place the batting-covered board face down on the fabric. Cut out a piece of fabric measuring three inches larger than your plywood frame on all sides. Carefully wrap the fabric to the back of the board and secure with staples around the perimeter.
Using a stud finder, locate the studs in your ceiling directly above the bed. Mark these spots with a pencil. Hoist your upholstered canopy frame to the ceiling. Nail the piece directly into the studs using drywall nails and a nail gun.
Cut small circles from your fabric. Place a small dot of fabric glue on the back of the fabric. Press these circles of fabric into the nail heads visible in your upholstered canopy frame.
Place one of your cut fabric panels cut face down on the work surface. Turn the panel, so the shorter edges are at the top and bottom. Fold the top edge over 2 inches. Pin in place.
Using your floor to ceiling measurement as a guide, determine whether you want your fabric panels to pool on the floor, creating a dramatic look, or just skim the surface of the floor. If you wish to allow the curtain panels to pool on the floor, fold up the bottom edge one-half inch and pin in place. To allow the panel to just skim the surface, fold the fabric up two and half inches and pin in place.
Fold the right side of the fabric panel back one-half inch. Pin place. Fold the left side one-half inch and pin in place.
Repeat Steps 7 through 10 with the remaining curtain panels.
Thread your sewing machine with a nylon or upholstery thread that matches your chosen fabric. Set the machine to a straight stitch. Sew along all of the pinned edges, removing the pins as you go. Repeat on the remaining fabric panels.
Line one of the adjustable-length curtain rods up along one edge of your previously-installed fabric panel. Screw the included brackets in place. Repeat on the remaining three sides.
Thread a curtain rod through the pocket you created in the top of one of the fabric panels. Hang the rod on the brackets you installed on the ceiling. Repeat on the remaining three sides.