You see one of my old tops, still has measurements on it. As well a new top, I am making for Incra setup. You see the template I use (it is plywood, because I have used it many times)
To make the template, just make the shape size you want, and use a jigsaw to cut out. Sand and shape it more if needed. Unless You mean something else, in tops?
The template using the PC guides, allows for exact copy, or undersized if needed.