I used to use freezer paper and a glue stick, but disliked needing to cut through the background after the piece was sewn in place to remove the freezer paper. I also found the freezer paper was not great for being reused. Especially where I have lots of the same shapes (other than circles), I recently switched to using Karen Kay Buckley’s template plastic and an iron with starch. She has videos showing her technique on her website. For circles, I really like my applipops.