How to face the UPSC Interview Board

Well for any first timer, the interview call letter of civil services brings immense joy and apprehension of what will happen in interview.What kind of questions will be asked and will I be able to answer those queries confidently and convincingly.
I have given interview twice in 2008 and 2009 and scored 180 and 159 in two contrasting experiences.So , first of all my heartiest congratulations to those who have got the interview calls.I would like to share certain points which i feel can help in getting a grip over the interview process.
First and foremost candidates should work on their Mains application form, which will be the first point of reference for the interview panel and from which the questions are most expected.Every single place, person, thing etc mentioned in the application form needs to be well prepared with background information.For instance I had done my education from northeast and many question were directed towards the problems facing North east. Also, I was quizzed on my hometown and why it was famous etc. So , the point is to be very well prepared with your bio-data. While the interview panel is not looking for people who know everything, but they are definitely impressed with candidates who show good understanding of themselves and their surroundings.
Another important point that I observed is being honest with the Board.Never try to bluff and take the Board for a ride ,because they are very experienced people and if your untruth is caught, you are going to be definitely out.So be honest , even if you are unable to answer a very simple question in the interview, say "i dont know" with a smile and that will have a much better impact than a mumbo-jumbo type answer.Not knowing is not a crime and they also don't expect the candidates to answer all their questions.
Keep your confidence going by being truthful and honest with your answers. Don't take extreme stands unless the Board is asking your opinion on issues like corruption, patriotism , constitution, democracy , secularism etc.
Its important to give few mock interviews to get a feel of the interview type situation, but don't let your performances in them to affect your morale. The mock interviews are designed to point your flaws and learn from them.
I would recommend taking mocks in any two from Vajiram, Sriram and Chanakya.Also few mocks from Samkalp would be handy for the candidates.
Final piece of advice from my end would be to take interview as a converstaion with a friend of your father, with whom you would be confident yet little formal while interacting and this is what is required in UPSC interview.
All the very best !!!