We were always told how the demons could infiltrate our thinking so we had to avoid anything that could connect us to them. So we didn't watch Bewitched (but I Dream Of Jeannie was ok). We made sure we never said "Bless you!" after a sneeze because that was another demon connection.
We avoided 2 door cars because it was (obviously) not a good service car.
There are plenty of things that you might think of to add to the list of no-nos for Jehovah's Witnesses. Any others??