Bev, I used cardboard for my template. Just cut an old box I had gotten from a fabric shipment. Just be careful cutting the cardboard. DO NOT ask me why I am saying this,,,,just take my precaution.
The templates I have DO have some rough edges, but when I am cutting them, that's when I "smooth" the edges.
I'm thinking of doing a sort of attic window with each block. Maybe embroider something different in each block. I dunno.