If you are coaching spokespeople, the only tip I'd give is to listen to the question and think about the response instead of being caught up in your own agenda.
If you are a photog or reporter, first thing in the room, have the photog put the wireless lav on the subject. By the time its ready to roll, they will forget its on. While the photog is setting up, have the reporter chit chat about anything but the subject of the interview. The reporter and photog should come up with a signal that it is time to start. I often didn't even tell the subject that we had started. The reporter just shifted the questioning into what we wanted. After a couple of on-topic questions where the subject had no clue that I was actually rolling, the reporter would turn to me and tell the subject that we were ready to start. The best results were from those first few questions.
Some may question the ethics of this manuver, but I'm convinced that if a camera is in the room, people should be aware that they can and might be taped. If a photog expressly says that they are not rolling, and then do anyway, that is a different matter.