If you've printed out the paper templates, there are couple ways to tackle this part of the project.
* If you're using the double-sided tape method, do not tape over areas where you'll need to punch holes. The tape will gum up your punch.
Cut out the paper pieces with scissors and punch out holes with a punch. Then carefully trace around the paper patterns on to the foam.
I find that it's much easier to tape the cut paper patterns to the foam temporarily with double sided tape. Then cut the pieces out with the paper in place. This way, you only have to punch the holes once.