As a consultant I have experience in both sides of the interviewing process. I have been the interviewee and interviewer in multiple occasions. One of the things I noticed is that no 2 interviews are the same and everyone has it’s own way of working.
What I always try to do, is to take some of the stress away when I’m interviewing someone. No idea if I’m successful in doing this, but I do my best. When people are put under stress, they suddenly can’t remember some of the easiest stuff. Making an interview a stressful experience will not give you good insight in the quality of a candidate.
If you want to improve your skills as an interview, have a look at this interesting (and funny) Channel 9 video: