One thing I found useful on a trial lesson (Baptism of the air in French) was to say just before take off that we would fly 5mins west and stay fairly close to a big factory there, and at the end of the lesson ask him to fly back to base, and after the initial shock and a bit of prompting, he would twig, "We'll fly for 5mins east!" It would give them a bit of satisfaction and be of benefit if they did take up flying.