You can get creative and use old doors or anything that you'd like. But if you want to create your own, you can cut three pieces of plywood to size - approximately 18" wide by 5 or 6' tall (use 1/2 to 3/4 thickness". Then install two to three hinges to attach the first two pieces and then do the same to attach the middle piece to the third - but be sure to do it on the opposite side so that you get a "Z" fold.

For the wood as you're cutting your pieces, you can cut fun shapes in the top with a jigsaw or even cut holes out of the top for an intricate design. Then you can finish off the edges with iron-on edge banding (found at hardware stores). Since plywood edges are laminated, to finish them for a clean look, this edge banding is simply ironed on with a hot iron then the excess is trimmed off with a razor or a laminate trimmer.

Then to finish them, you can stain or paint solid, with designs or faux paint - whatever suits your room. Good luck!