When I built mine I used finish nails, glue, and clamps. If you get the right size finish nail it is nice to use that to help hold things together enough to allow you to get the clamps on. Room treatments were fairly cheap. The wall pannels are 3/4 inch soundboard with a 1x2 frame around the back with a couple braces in the middle, then they have a batting material over them with fabric covering that. The traps are 15 inch pieces of MDF on top and bottom with 1/2 x 1/2 inch wire fabric wrapped around that and with 4 2x2's between the two on the inside for support and for something to staple to. Then I wraped them with batting, then with fabric. Stuffed with fiberglass insulation.