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.
A story board for your table saw. Set your fence for the appropriate cut, then run this jig through it for a couple of inches. Makes setting it up again quick, simple, and repeatable. Dont forget to label each cut. - My Wood Crafting