Thinking Skills Assessment, 2x interviews
A mix of source-based questions
Read around the subject and revised key notes
Completed timed practice papers
Read books around your subject
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:
Number of interviews: 2
Time between interviews: A few days
Length of interviews: 30 minutes
Online interview: Yes
One of my interviews was more 'good cop' and the other more 'bad cop'. I had a mix of questions and talking about sources - one of which I had a few minutes to read through in advance. The interviewer would wait for your response and then prompt you in the direction they want to take you towards finding an 'answer'. Try to say your thinking process outloud - even if you have no idea what the answer really is!
I did a
I also made sure to read around my subject and jotted down some key notes/facts to revise for the interview that I could apply to questions where possible to show my further reading.
Lots of practice papers (did sections under timed conditions)
The interviewers are looking for somebody keen and interested most of all! I would advise you to read books on your subject and keep up to date with current breakthroughs etc. Then just practice answering questions on your feet.