Lay a piece of plywood on a worktable and turn it so it faces side to side. Measure it using a tape measure to determine the height. If you desire a shorter headboard, draw a line at the desired cutting location using a pencil and cut the plywood down with a power saw. Always wear safety glasses when cutting wood.
Measure the width of the plywood to ensure that it is at least 4 to 5 inches wider than your mattress, which is the proper width for a headboard. If needed, cut the plywood down to the proper width using the circular saw.
Lay a large section of upholstery foam flat on the floor, ensuring that it is slightly larger than your plywood headboard. Lay your plywood on top of the foam and trace around it using a black marker. Move the headboard aside and cut along the marker outline using a sharp utility knife.
Open all windows and doors for ventilation, or move the foam and plywood to an outdoor location. Spray the surface of the foam with a spray adhesive until all portions are covered. Place the plywood on top of the foam, aligning the edges perfectly. Press down to secure the wood to the adhesive.
Spread out a roll of batting until it is in a single large square on the floor. Place the headboard on the center of the batting, with the foam facing downward. Cut around the perimeter of the headboard using scissors, leaving 5 inches of batting around all sides.
Wrap the batting over the back of the plywood until it is tight. Secure it to the plywood using a staple gun. Work your way around the perimeter of the headboard, wrapping the batting over the top and securing it with staples spaced every 3 to 4 inches.
Iron your chosen fabric to remove all wrinkles. Lay the fabric on the floor and place the headboard on top of it, batting side down. If needed, trim the perimeter of the fabric until there is only 5 inches around the headboard. Wrap and secure the fabric using staples just as you did with the batting.
Turn the headboard over so the finished side faces up. Insert upholstery tacks along the entire perimeter of the front edge with the sides of the tacks touching each other. To insert the tacks, press them in as far as you can and tap them gently with a hammer.
Turn the headboard back over and install two flush-mount brackets on the back, approximately 2 feet apart. The mounts attach via screws inserted into the plywood. Use a tape measure to identify the corresponding locations on the wall and insert two more flush mounts into the wall using the screws provided. Lift the headboard up and slide the brackets on the headboard into the brackets on the wall.