Multi-sized Hole template
My jig/template for cutting out smaller holes of almost any size is made by cutting a hole of each diameter with a set of holesaws and then using bushes of 10,14 or 20mm dia with (usually) either a 6,7,8 or 9mm straight cutter. this provides for any size hole from about 60mm down to about 6mm.
I find it best to mark out the vertical and horizontal centre lines for each circle with a marking knife so as to aid in positioning the template. Hardboard will do, varnish it if you want!
Photo of template below.