what is the best starting point to make a paper hole puncher?
Baaper? Ask this guy, he is a baaper expert and lover.
Answered with a tutorial: https://grabcad.com/tutorials/how-to-make-a-paper-hole-puncher-in-solidworks
I think punching rods. Start from punching rods; becouse its has standart and all dimensions already defined.
Find a paper puncher, take it apart and make a model from the dimensions using a caliper