Prepare ahead of time. Have a copy of your resume and reference list in front of you so that you can review it along with the interviewer. Have a list of questions about the employer and the unit. Be ready 15 minutes or so in advance. Send the kids to grandma's and put the dog in the basement so there are no distractions or noises. Disable your call waiting. Put a note on the front door not to ring the bell. Go to a quiet room and get in the mindset. Have a glass of water handy in case your voice cracks.
Unlike a face-to-face meeting, the interviewer has only your voice by which to evaluate you. Speak clearly. Don't rush. Be cheerful, but not fakey. Take a moment to think thru your answers before speaking. If you need an extra moment to phrase an answer, say so. Remember, your body language won't do that for you, you must speak up to let the interviewer know that you are thinking. Likewise, if you are stumped by a question, say so and ask to come back to it.
Conclude the interview as you would a face-to face. Express your interest, ask what the next step in the proces is, and when you can expect to hear from someone. Confirm the name, spelling
and contat information of the interviewer so that you can send a timely thank-you.
Hang up and crack open a cold one