Pictured is a fly that settled on the side or a vertical roll of paper towels located on a table in a restaurant as napkins. I probably would not kill a fly in a restaurant, but a fly swatter would not have worked well in this situation. Chances are, the swat would have knocked over the roll of paper towels, which would have knocked over other things on the table and made a big mess. But, a rubber band fly killer would have made the job easy, quick, and precise.
Step 1: What bands to use
Step 2: Join the bands
The rubber band fly killer works best if the rubber bands are new. Several times I had aimed and drew my fly killer ready to strike when one of the rubber bands snapped because it was old and deteriorated. The fly usually escapes in those situations.