#10 for a thumb plane now, remember when they were only$5

possum Iuse my band saw to rip 3/8"x3/8" squares and then like Pat said use the thumb plane to round it, I made a device to help align and hold the blanks,
router a V groove in a board and put a small nail in one end for a stop. works pretty good.
I also made a die to run the blanks thru with a drill, a steel plate with holes drilled in it descending in size by 1/32" each time. Then use a bigger bit to kind of taper each hole, stop at least one size bigger than what you want and sand to size.