To sand circles, strap on this gritty "bow tie"

If you need to sand the inside of a large hole for finishing, you can use your fingers and a good deal of patience, but usually, the results will be uneven. A better and faster solution is to use the technique shown. Cut a piece of 3⁄8" dowel rod 4–6" long and use a bandsaw to cut a slot into the end of the rod. Next, take a strip of cloth sandpaper and loop it into the slot so that the loop is slightly larger than the hole you want to sand. Install your hole sander in a variable-speed drill and let the sanding loop smooth the inside of the hole. —Daniel Kingsberry, Gatineau, Que.