I round my corners so they are nice and smooth (as possible). When I hold the reel I keep a couple fingers on the outter walls of the reel. If the film does jam up a bit you can feel around to where it is stuck. Just push in a little bit and it will start going again. But rounding the corners really helps alot. Oh and try not to cut through a hole. I readjust my cut if I just happen to cut through one. I have always done 36 on the plastic reels and have never had one that gave me fits. When they do stop just feel around and push in. If you keep a couple fingers on the flat side of the reel you can feel the film winding around.