MLAT; 3x interviews.
Interviews 1&2: literature analysis, personal statement discussion; Interview 3: beginners' language - focusing on grammar and language analysis. Felt supported and guided through.
Got used to speaking aloud; re-read and felt confident about personal statement; re-read submitted work.
Think aloud and make sure you express an opinion rather than saying you don't know; be flexible and enjoy the experience.
Remember this advice isn't official. There is no guarantee it will reflect your experience because university applications can change between years. Check the official Cambridge and Oxford websites for more accurate information on this year's application format and the required tests.
Also, someone else's experience may not reflect your own. Most interviews are more like conversations than tests and like, any conversation, they are quite interactive.
Test taken: Modern Languages Admissions Test (MLAT)
Number of interviews: 3
Time between interviews: 3-4 hours maybe?
Length of interviews: 30 minutes roughly
Online interview: No
Two interviews focused on literature analysis, I was given an unseen text before my interview and asked to discuss it with the tutors during my interview. The tutors guided me when I was stuck or when they could see I was struggling, they often provided their own ideas to see how I reacted to different points of view, this never felt critical or condescending, it just felt like a discussion. One of these interviews also focussed on my personal statement and the texts I had mentioned, the discussion was largely determined by what I wanted to talk about, which was nice and I felt very relaxed. My third interview (for a beginner's language) focussed on grammar and language analysis, the tutors were very relaxed and again guided me through aspects where they could see I was struggling. I didn't think this went particularly well but I didn't feel stressed during the interview, I'm pretty sure I actually laughed a lot at my mistakes and terrible German pronunciation.
Spoke aloud about my subject A LOT (even just to myself), to get used to talking about it at length out loud. Made notes on my personal statement (texts I'd mentioned etc.) so I was prepared to talk about them. Read the written work I'd submitted and responded to comments which my teachers had left when they marked them, generally thought more deeply about the topics I'd submitted written work on so I could say more about the topics if asked.
Lots of practice papers and working on grammar areas I knew I wasn't very confident in.
Give yourself time to think but don't be afraid to think aloud either, the tutors want to hear what you think! Try not to answer anything with 'I don't know' if you can, it's better to express an opinion (even if you think it's wrong) and be asked to think about it in a different way rather than shoot the question down completely. Don't be afraid to change your opinions either, it shows you can think critically and you're open to other points of view. Also, enjoy it! You're having a discussion with someone who is an expert in this subject area, so even if you don't get in you can definitely learn from the experience.