Place the 1-inch by 10-inch by 24-inch board with the 1-inch by 24-inch edge flat on a work surface.
Position the 1-inch by 10-inch by 12-inch board at one end of the 1-inch by 10-inch by 24-inch board with the 1-inch by 12-inch edge flat on the work surface to create a backward “L” shape.
Drive four evenly spaced wood screws through the bottom of the 1-inch by 10-inch by 12-inch board into the end of the 1-inch by 10-inch by 24-inch board, using a screw gun.
Sand the assembly with fine-grit sandpaper in the same direction as the wood grain until it is smooth.
Apply a wood finish to the assembly, using a paintbrush. Allow the finish to dry for 24 hours.
Install two evenly spaced keyhole slots on one 1-inch by 12-inch edge of the 1-inch by 10-inch by 12-inch board by driving the provided screws through the mounting holes in the slots into the edge of the board. Install four evenly spaced keyhole slots in the same manner on the same 1-inch by 24-inch edge of the 1-inch by 10-inch by 24-inch board.