For making multiples, that is exactly how I do it.use of jigs to make all relevant pieces the same length, width, holes in the same place etc
For one time, I often just cut close to the pencil mark, then carefully sand down to it. That normally gives me the accuracy I need/desire. Sometime in the near future I will be doing a small octagon of 1/2" plywood, just that way. I have several patterns glued down, so have some spares until I get it perfect. Then once I get a perfect piece, it will be used in making a jig/master so I can clone as many as I want, with no need for measuring or marking. They'll be used for chess piece bases, and checkers.