The shorter your comments, the less likely they are to be edited. Even print reporters are looking for short, snappy quotes. Remember that you are the expert. Be colorful - tell stories and anecdotes that illustrate your point. Stick to your main points and do not allow yourself to get drawn too far off on tangents.
Most people make the mistake of talking too much.
Repeat your points if necessary to get back on track. Speak in complete thoughts. Reporters' questions may be edited out and your response should stand-alone. Don't overestimate reporters' knowledge of your subject. When reporters base a question on information you believe is incorrect, set the record straight.