Slice up the rafter using the circular saw. Wear protective goggles to avoid debris flying into your eyes. Depending on the size of the shelves you may need more than one rafter. Cut 1/2-inch-thick slices. Ideally, each slice should be 3.5-feet long, but you can change the measurements according to your own needs.
Sand the wood slices using the sander and the sandpaper.
Apply the varnish using the brush. Use a face mask when applying the varnish as it may contain chemicals that can be harmful to your lungs.
Screw the shelf frame to the wall. Follow the manufacturers instructions. You can get wooden or metal shelf frames from any furniture store. The distance between the shelf frames should be 10 inches shorter than the length of the wood slices.
Place the wood slices onto the shelf frame.