Yes I agree with most on this one, actually when I used to do Trial flights I never went to a briefing room, straight to the a/c and a "hands on" briefing using the a/c as your model, but it's quite right that each flight is different, they range from not wanting to touch the controls to sending you into massive aerial dogfighting routines. The key is to guage the student individually and give him/her as much control as possible, after all the more fun they have, the more likely they'll return.