Being a successful applicant to Cambridge, I think it's only fair that I spill a few secrets about the interview process for the benefit of others. I'm not a current undergraduate; my interviews were last December, so I haven't secured my place yet. I'm actually in the middle of the exams that should determine whether or not I make it there. But since my interviews were so recent, I'm in a good position to advise you...

1) Firstly, choose your course well. This may seem like an obvious piece of advice, but I assumed I'd be doing History until I saw the page on Anglo-Saxon, Norse and Celtic. Look carefully at the course descriptions in the prospectus, including what grades and subjects they prefer you to have.

2) Secondly, choose your college well. This is often overlooked by people who live outside of Cambridge - they assume it's not very important. It is. Each college has a different atmosphere, ranging from the posh and traditional (Trinity, St John's) to the laid-back and casual (Fitzwilliam, Churchill). Some colleges are in much better locations than others (Girton is several miles away from anywhere, while King's is right in the centre), and some have much better facilities than others. Some only accept women (Newnham, New Hall). Consider all these factors before you choose. I would also consult the college league tables (often in Oxbridge guides) to find out which colleges are 'harder' than others to get into.

3) On the application form, don't worry about the photo; concentrate on the personal statement. If you're applying for a very popular subject (e.g mathematics) the interviewers will have lots of applications to read - yours must stand out. Don't just put you UCAS statement on there - if they read both you'll look like you've made no effort. Mention why you want to study the course, and what evidence there is that you're seriously interested in the subject (e.g
relevant work experience). Mention also some varied hobbies and experiences so you don't look like a bookworm.

4) If they ask you to send in work, then take your best essays and improve them as much as you can (unless they specify marked class essays, in which case you can't improve them). Don't send in any essays that are much more than 2000 words; the interviewer won't want to read anything too lengthy.

5) Practise your interview technique. This cannot be over-emphasised. You should try and get as many adults (preferably slightly imposing ones that you don't know well) to interview you as you can. A teacher at your college is a good start. Even if they're not a teacher in the subject you wish to study, they will provide practise for your general interview. Make sure that you can talk intelligently about everything you've mentioned in your personal statement, and about any essays you sent in. You should be able to explain why you wish to study a) that subject and b) at Cambridge; why you go to aerobics classes or collect stamps; why that trip to Russia was so inspiring; and how that work experience affected your decision to apply.

6) The best thing is to get a real Cambridge academic to interview you as a practise run. For most people this isn't possible, but as I live in Cambridge I had enough contacts to get me a practise interview. Sometimes, if you impress enough, the academic will put in a good word for you (this actually happened to my sister). What was revealed to me at the practise interview is that all interviewers have set criteria for acceptance. You must a) demonstrate real enthusiasm for the subject (you can show this by relevant work experience and by generally being really upbeat in your interview); and b) demonstrate that you are teachable (you can show this by listening carefully to the interviewer and his/her opinions, and by modifying your opinion if the interviewer shows it to be wrong).
These are the main points you are marked on.

7) Don't worry about the small details of the interview. Often, you won't be given specifics of where your interview is. Just go to the college and there will be people there to look after you. Don't worry about the way you're dressed - as long as you're not in jeans and a t-shirt, they don't really care. After all, it's not as if you can make up for a bad performance by your ability to accessorise. Forget what you might have been told about Cambridge being a labyrinth of rules and customs. It's not, and the interviewers understand that you're new to the place and a bit intimidated. They'll make a few allowances. So relax, eat a good breakfast, and do confidence exercises. I find that dancing around in my room to Mariah Carey does the trick.

8) If you realise mid-sentence that you're waffling, then stop, say 'I'm waffling', think, then re-start. When you're asked a question, give an extended response (although make sure it's appropriately extended). If you don't know what to say, then say, 'That's an interesting question, I hadn't considered that before...', think, then say something. Sit slightly forward on your seat, because you'll look more alert and concentrated. If you're not sure what they're asking, say 'Do you mean...?', not 'I don't understand you'. Those are the more basic tips. In general, just remember: enthusiasm.

Lengthy advice, I know, but for many people the interviews are scary unfathomable things. The simple steps I've outlined should improve your performance, if only because knowing more about the interviews should increase your confidence. Cambridge is a great place, and a place worth fighting for, so give it as much effort as you can.