I did the carr communications training course back in october. I learned all the "tricks" and "answer formulation" techniques that one would expect to learn from attending such a course. However I did not use ANY of them when it came to the interview, which has subsequently transpired into an offer. The best thing I got out of carr communications, is being absolutely grilled by my coach. At least I felt it was really tough but then again I hadnt done any interviews prior to it. (however some pretty experienced interviewee's have since watched the dvd and confirmed its "BBQ" status)
I came out thinking, "an actual interview, could not, in anybody's worst nightmare be THAT hard"....that helped me and relaxed me, when preparing for the actual interview. They wont grill you intentionally, but my advice is MAKE them do it, by either asking them politely or by doing what i did.
I had never been to an interview (thats not to say i havent had jobs) prior to going to carr communications and I intentionally got my coach to dislike me before he conducted the mock interview, by being cocky and arrogant, because I knew that to get my €150 worth of hard earned cash, I needed to get something more out of there than "skills and techniques" that I already had a fair idea about from talking to experienced people. I know that that wouldn't be everybody's cup of tea but I felt that if I got through that (and he said that I actually did reasonably well considering it was my first interview....), I could surely do better at and be more mentally ready for an actual interview. Conquer you fear/nerves and you'll conquer the interview-thats my advice. Aside from that, the last poster is completely correct in saying "know your cv and be natural"-you cant go wrong.