Two different interviews (one in the early morning and one just before lunch). When I arrived in the morning I was one of the first people there, so I asked the Porter's Lodge directions to the JCR from the Porters' Lodge, and found a couple other people on their way to the interview going to the JCR.

The wait in the JCR was pretty quiet and nobody was really talking even though the room filled up with interviewees fast. A first year came and took me to the office where my first interview was. There was enough time after it to leave and go get a coffee in the town.

When I returned to the JCR for the second interview, it was busy and chatty as some first and second years had come down to keep the interviewees company.

Each interview took around half an hour. There were supposed to be two interviewers at each but for the one interviewer was sick for the first one. Both interviews were technical.

The first interview began with a a quick discussion about a book I had mentioned in my personal statement. Then there was a written maths question about functions/graphing which wasn't too bad as I had done similar questions in school.

Then there was an unfamiliar biology question about a medical technique (the only prior knowledge needed to answer it was a chemistry equation). There were then some follow up questions to the first biology question.

The second interview began with a chemistry problem about chemical compounds. There was then some discussion of evolution and I think a couple of other chemistry problems.

Reading popular science books. Going over school notes. Looking at online practice Oxbridge interviews. Mock interview with my parents.

It seemed to me that the most important thing was to vocalise all your thoughts. Treat it as a journey/discussion rather than trying only to give the final/correct answer.