This is a cool headboard that would be fairly easy to make. You would just need to use some molding, and cut the ends at a 45 degree angle, from here you’ll just put all the ends together to make a large frame. Then you can pick the fabric, and layer your wood or cardboard, then add batting, then the fabric. This would be a good afternoon project that will make such a big difference.
I love this look. Using old barn wood just nailed up to the wall. I love the contrast of the white bedding too.
If you want to have the look of a headboard, but want a quick project, then just stain some molding look old, then stencil the wall, and it’ll look like a framed in unit attached to the bed. This is definitely the cheapest way to make your bed look finished.