Prepare for the interview.
The first thing you need is to write a list of questions for the media. Most publicists will write questions for you—and you'll be able to tweak or correct them.
Or you can do some kind of collaboration. For example, a publicist may see ways to promote your book that you hadn't considered. Or you may want to focus on a significant aspect that the professional missed.
In my early days, I prepared 20 to 25 questions and realized that hosts rarely moved past the first dozen, even if they went right down the line with the questions. Half that number is where I now focus. That is, I try to write sharp, significant questions and emphasize the message I want readers to get from my book.
I rarely write questions on books for which I collaborate, because I don't seek interviews for myself. However, Don Otis, a publicist, is setting up interview questions for Stolen: The True Story of a Sex Trafficking Survivor by Katariina Rosenblatt and Cecil Murphey (Revell, 2014). Because I think that's such a powerful book, I'm willing to do interviews. But that's the exception.