It's less likely to stick too tight if you use a dry iron. If it does stick so much that it's difficult to remove, spray it with a little water. That should loosen it up enough so you can remove it, but it will probably tear so you won't be able to reuse it. According to Susan Cleveland, freezer paper will shrink slightly when it is ironed. If real precision is a concern, preshrink your freezer paper before making your templates by ironing it to the ironing board with a hot dry iron (no steam). Let cool, peel off, and make your templates.
Julia in MN