A few "tricks" you might find helpful. Assuming you use your left hand to hold and manipulate the reel, and your right hand to hold the film, try this. First, make sure the open end of the spiral on the SS reel faces to the right. Once the leading edge of the film is under the clip, use your left-hand thumb and middle finger to feel the centering of the film in the center of the reel, and reposition the film if needed. Then, make sure the film is clipped such that it's square to the reel. Try to keep a slight, even tension on the film as you rotate the reel, and rest your right-hand thumb and index finger, used to guide the film, on the edge of the reel. That will prevent having too much arc or "pinch" across the width of the film. You want just enough to clear the outer edge of the reel.