Just because you’re immersed in some subject every day doesn’t mean you can spontaneously pull on the right threads to weave a public performance.
The fundamentals always come down to preparation. Whether you work with a professional coach or prefer to go it alone, invest time and effort in rehearsals. Get your spouse or partner or a trusted pal to lob questions at you. Make sure those lobs have some zing. How will you respond to tough or hostile questions? Do you have a clear, honest and appropriate answer to the most negative query you can imagine?
Plan your answers with key messages and try to second-guess supplementary questions. Make sure to research your listeners and their expectations beforehand. In any interview, you’re really speaking via the reporter to his or her readers, listeners or viewers. Videotape your performance and use the results to make changes.