I actually preforate my freezer paper with the unthreaded needle of my sewing machine. You can make several pattern pieces at once by stacking up the freezer paper and touching the tip of a hot iron in several spots. I have gotten up to 5 sheets to stick together this way. On my top sheet (shiney side up) I usually place a tracing or copy of my original pattern. I then stitch along the the lines for preforation of my freezer paper. I have never attempted to piece the freezer paper method without preforating it. I can imagine you would get very frustrated very quickly trying to fold exactly where you needed to fold.
Judy Mathieson has detailed instructions on this method in her mariner's compass book "Setting a new Course". Ever since seeing this method I try to PP with freezer paper whenever the pattern seems friendly to it. I much prefer it to not having to tear off paper when done and I love the idea of being able to reuse the pattern pieces up to 8 times before they quit sticking.