A few months ago, my husband and I bought a king size mattress and box spring. We are now building a tufted headboard for it. To be honest, this contest is the motiviation we need to finish the project!
I found a tutorial online that uses pegboard instead of mdf or plywood. The pic is from the tutorial. The pegboard makes it so much easier and faster to create the tufts in the headboard. We used a circular saw to cut the pegboard to the right size, and then we used spray adhesive to attach an egg crate mattress topper, which I cut in half and used both halves for extra thickness. The topper was a lot less expensive than buying thick foam at the fabric store.
To finish, we need to cover the headboard with fabric, make the fabric-covered buttons, and attach the buttons using heavy-duty thread and a staple gun.