I recently did a phone interview for a marketing internship. Boy, was I unprepared for what they asked. I guess I just didn't do enough research. My advice would be to use the STAR method, and isolate incidents in your career that you can apply to different skill sets. Have these readily available in your mind before an interview.
S-Situation-describe a specific situation that applies to the question asked.
T-Task-describe what the task was.
A-Action-describe the action you took.
R-Result-describe the end result.
Believe me, this is incredibly important. I had always been told that questions like, tell me about yourself, or why did you apply for this position were more common. This interview was 8 standardized questions that isolated specific situations. It is essential to prepare, because otherwise you'll stutter through the answers and try to come up with something quickly like I did. Phone interviews are difficult, but be prepared for not only basics, but situation and outcome questions. Regardless, I did get a second interview, but if you blow everything else, just try to establish rapport and remain enthusiastic. Don't give up on yourself like I almost did! You just never know.