We all know it is easier to fly without passengers than it is with passengers. I don't involve the passengers at all. A passenger is best left in that role. Have a plan to do as much as possible in advance, and to completely assume the role of aviator once the passengers are buckled up and settled (care not what the passengers think). The nurses and medics who are professionals, and they are few, understand that flying requires a certain degree of concentration and they speak only when spoken to. Be sure that the passengers understand that chatting is allowed only when instituted by the pilot.