I have given enough interviews and find a stricking similarities between them.
Here are some of my experiences and my techniques to get the interviewer interested in me.
I am a Unix/ C guy so will give examples from my field only.
Prefer Telecon: Admit it that you are generally nervous during the interview. Not seeing the interviewer will definately put u at ease. Aslo as the interviewer cannot see you, he cannot make out that you are nervous. Its positive either way for you.
Be Confident and nothing more. So the interview has started and you happen to know the answere to the first two questions, WOW!!. Stop!! Relax. There is no need to be overjoyous. This is a great begining and nothing more. Your will try to attempt the next answer, full of confidence and voila, you know the answer for that too. Do not over answer. Never. We try to tell the interviewer too many things which we know only periferally and try to integrate all that in our "Confident answer". The interviewer might get impressed, but just in case, if he probes you further on the topic, you are gone. Remember one very bad answer negates three good answers. Better not to speak those words. Moreover, if you know the answer and answer "Too Confidently" it might be offensive to the interviewer, he is after all a human. For instance once I was asked "What is a Virtual Destructor?" I found that question very easy and started with "Oh its simple ......", I never had a second round.
Stress on the topics you are strong in: Continuing with the previous example, If the interviewer asks you a simple question and you have very good knowledge in that area/ related area. Give subtle hints in your answer so that the interviewer may catch a word or a phrase and further probe you in the same area. For eg. If he asks the same "What is a virtual destructor?", frame your answer in such a manner that it includes brief explanation of what Virtual functions are in general, virtual pointer, virtual function table, and why virtual destructor is different from other virtual funstions. Apart from impressing the interviewer, it will also give him a few questions to ask. If he misses the first hint, then don't loose hope in the next answer try to include words like RTTI, dynamic_cast, safe downcasting etc he is bound to fall for this and will ask further questions. Now that you have answered few questions convincingly, he is impressed. The above text assumes that you have good knowledge of Virtual functions and Inheritance. Lastly, these are valid only if you interviewer is a Male, for female intervieweres have a fixed set of questions and do not deviate from it.
Say No: NO is a great keyword. If you do not know a question or an area say NO. It you try to befool the interviewer and he catches it, BYE. NO also indicates to the interviewer that you are being honest and are ready to accept that there are areas/ questions which you are not very proficiant at.
Give a clear picture of your current role: If you are good in Unix and work mostly on networking, say it and say it confedently. Even if the project for which you are interviewed does not involve networking to a great extent, the interviewer will try to restrict his questions to networking on Unix. On the other hand if you mention Databases, GUI in your resume, the interviewer definately will ask question on it. If an interviewer asks me questions on GUI I know it is the end of interview for me.
Always mention your achievements: So you have UML certification -- mention. you have send a linux kernel patch-- mention. You are part of open source project -- mention. And last not the least, if you have authored/ co-authored / co-co-co authored any Article/ Paper/ Patent explicitly mention it. These raise your level and normally work in your favor. Never think that interviewer will read it in your resume always mention it during the introductory phase of the interview.
Will add more to it. For the time being-- Sionara.