To be honest i'm a little bit disapointed,i try to make the briefing fairly short,[twenty mins] concentrating on the basic controls, and what to expect in the lesson, i'm fairly knew to instructing, but so far, when i ask any questions?, the only two responses i have been given, have either been no, or will we be flying over my house, conclusion: ninety-nine percent of trial lessons are really joy flights, and at the end of the day, although a briefing is a bonus, i suspect it makes little difference to the average customer, BUT there is always the one in a hundred, and we owe him/her.