Draw a circle with a square - Tack two nails to set the diameter you want, then rotate a framing square against the nails while you hold a pencil in the corner of the square. Rub a little wax on the square so it slides easily.
Would take a very sharp chisel and a lot of patience. Beautiful look, though. Stockholm Furniture & Light Fair 2014 Budding designers shine with bright colors, smart materials and folklore inspired themes