Set the bed against the wall and use a tape measure to determine how tall and wide you want the headboard to be. For instance, may want the headboard to be only as wide as the top of the bed or you may want it to be wider. The headboard should be tall enough so that it can be seen past the top of the bed when pillows are in place, so placing the pillows on the bed while taking measurements may help you determine the height you want the headboard to be.
Purchase a sheet of corrugated metal from a home improvement store. Ask a professional at the home improvement store to cut the metal to the measurements taken in Step 1.
Smooth the edges of the cut metal with a fine metal sander.
Position the headboard in place behind the bed. Pull the bed away from the wall about three inches to allow you to move the metal into the position you want it to sit. Once you determine the location you want the metal sheet to sit, run a pencil along the top and bottom of the top and sides of the metal. These pencil marks will serve as a guideline when securing the metal to the wall.
Pull the bed completely away from the wall. Drill a type A self-tapping sheet metal screw into each of the corners of the sheet metal; use the pencil lines to ensure the metal is positioned in the right location while screwing it in place.
Screw type A self-tapping sheet metal screws every six to eight inches along the top, bottom and sides of the metal to further secure it in place.