Place the four 2-by-12-inch wood boards on the ground parallel to each other. Rest each board on one of the 2-inch sides. Space the boards about 20-inches apart.
Examine one piece of plywood and determine which side is smoothest. Set the plywood on top of the four boards, smooth side up. The two 12-by-2-inch boards on the ends should evenly line up with the plywood’s short sides.
Attach the boards to the plywood with the drill and screws. Use three screws per wood board. Put one screw on each end of the wood boards and one in the center.
Flip the plywood and wood boards over, so that the smooth side of the plywood is flat on the ground and the four boards stick up.
Set the other plywood sheet on top of the four boards in the same manner as you set the first sheet on the boards.
Attach the second piece of plywood to the four wood boards with the screws and the drill. As with the first sheet, use three screws per board.
Turn the bed frame back over, so that the smooth side of the plywood faces up.
Paint the bed frame the color of your choice using a paintbrush. Don't worry about painting the frame’s bottom or deep inside of the storage area. Let the paint dry overnight.
Set the twin mattress on top of the bed frame, centering it on the frame. Four inches of frame will extend from the two sides of the mattress and 4 inches will extend from the matress’ top and bottom. Slide the storage boxes into the four cubbyholes in the frame.