Turn or whittle a dowel to the right diameter to fit the area to be shaped or
polished. Cut a slot down the center. Slip the end of a strip of emery cloth
into the slot and wrap the tail clockwise around the dowel. Mount it on a
mandrel, clamp it in a chuck, or if you are really into it wrap a bow string
around it like a fire starter.  With 60 grit cloth it will rough grind. Step
through the grits.
Sharp grit cuts faster and cooler. Emery is cheap. Change it often.