I have used a Watson loader for years. Simply count the turns while turning the crank, one turn per exposure and add one or two for contingency. The portion of the casette spindle that sticks out faces down. Attach the film to the spindle with a length of masking tape, place it in the casette and snap on the end piece, and gently push the excess film back through the feed slot to place the casette directly beneath the crank hole with it lips against the loader's film exit slot. Close the door, insert the spindle crank being sure it engages the tab in the film spindle, and then count turns as you load film into the casette. Simple and works well. Keep the felt clean or don't get it dirty in the first place and you will not have any scratches unless there is grit on the felt of the casette lips.