I concur with Brian’s tips. All good stuff. I would add two things:
(1) No matter what jargon the journalist or interviewer uses, don’t follow suit. I once mistakenly took the cue from an interviewer who mentioned Paulo Friere to assume that that was the level of academic reference I could make in an interview for public television. The producer walked in afterwards and said, “That was good, but it was a little academic for our audience.” Oops.
(2) Make sure you realize/know how you look for a video-taped interview. Same interview as above: the buttons on the lovely sweater I was wearing gaped a little more than I would have liked. Nothing risque, but I wasn’t happy when I saw the footage. Also, it looked like I was slouching the whole time even though there was no way I’d describe my physical engagement during the interview as “comfortable.”