1. Base-coat the wooden disks in the desired colors. Let dry; add a second coat if necessary.
2. Stamp a letter in the center of each disk, using the permanent ink pad. (If you like, leave some disks unstamped. Paint them with simple designs, like stars or circles.)
3. Glue a magnet to the center back of each finished disk. Spray each top side with a coat of varnish.