I use tracing paper, it doesnt take as long as you might think. Then stick it to the wood using 3M77 spray adhesive or something similar. Just a light dusting of spray adhesive. You dont want the templete stuck on so good you cant get it off. I cut to within a 1/16" or so then finish sand up to the line with a 1" verticle belt sander. On parts that are the same, I can stack and stick them together (with spray adhesive again) up to about 4 high with out too much problem and finish sand to the line. But you have to be absolutely sure the verticle belt sander is properly adjusted. I've seen some guys us a router table with hard templates, which would be good for multiple planes being built. I've also seen guys us an oscilating drum sander. Lots of ways to do this.
Edwin