Measure the width of the wall where you want to mount your shoe wall.
Cut a length of 1x2-inch board and a length of 1x4-inch board matching those measurements using a hand saw.
Sand the boards using 100-grit sandpaper.
Paint the boards, if you wish, using paint and a paintbrush. Paint them white to match existing trim or paint them in a bold color to offset your room.
Screw at least two L-brackets to each board, spacing them evenly along the boards' length. One leg of the L-bracket is attached to the board while the is pointed down. When the boards are mounted to the wall, the L-brackets are invisible when viewed from the top. The leg not screwed to the board is screwed directly to the wall.
Screw the boards to the wall using L-brackets, screws and an electric drill. The narrower board should be situated two inches above the broader board. Use the shoe wall by pushing the shoes into the gap between the boards, toe first. The boards hold the shoes in place.
Repeat this process to create a shoe wall that covers as much space as you like.