As a writer/author and radio host I get to see book promotions from both sides. I am always marketing my books, and I'm also getting pitches and press releases from other authors and PR companies. Here are a few suggestions that I have for authors based on both experiences.
1. Never send a press release as an attachment. Media people delete these immediately. It takes time and computer space to download them and open them up, and many attachments come with viruses so who wants the bother? Put your press release in the body of an email and give all the appropriate contact information in case someone wants to see more.
2. Think of the newspaper/radio/magazine audience's needs and desires FIRST. How does your book address those? How will your book help that audience or resonate with them? Put that in your pitch. "Your listeners need..." or "Your readers want to..." and finish that sentence so that the person on the other end knows you've done your homework and realize what their audience wants to hear. Always think about how your book will solve THEIR needs and problems and pitch accordingly.
3. If you've been lucky enough to get a spot on the radio or TV, don't assume that the host will lead the entire discussion. Provide them with bullet points for discussion. Make their job easier. Send them an extra book or two to give away.
4. Go heavy on the local contacts. If you want to have your book featured on NPR, for example, start with all of the regional NPR programs in your area. Don't just send a book to a national program and leave it at that. Send letters and books to all of the local affiliates first. Provide them with talking points that relate your book to the concerns of people in their listening and reading audience.
5. Always come prepared with stories. Short stories about how you came to write the book, how the book relates to local people and places, or how your book fits in with what's happening right now in the area will help cement the book in the audience's memory.