The role of the Oxbridge mentor at our school -
- There was a talk back in about Feb which was all very blunt and quite doom and gloom and seemed basically designed to put people off if they had any delusions about the process - ie, if you’re not going to do super- curricular / essay competitions / extensive reading around the subject, don’t waste our time. Similarly, if you’re not going to spend half-term preparing for entrance exams, don’t waste our time and if you don’t have at least two A* predictions - well don’t bother. That was the general gist. To ram the point home, they brought back students who had eventually got in, but not in straightforward ways, to talk about the “journey” - which sounded quite traumatic in some instances.
So, that probably put off at least half of the prospective entrants. DS left that meeting saying he doesn’t feel he has what it takes to apply.
He changed his mind when he saw that other unis such as Durham, UCL etc ask for the same grades anyway. Also there’s not the hurdle of admissions tests for his subject do that’s a non-issue. He’s not overly phased by competitive interviews as most of the kids round here do at least 5 at various schools (sometimes all day long) just to get a place at a school at 11 plus 
I think they were given a sheet with some tips about how to write an Oxbridge PS. He gave his to his subject teacher in the first week back and got about 3 comments for changes which he made. The Oxbridge advisor role is not to read / give feedback on PS as he’s not an expert in all subject fields (I think he’s a Physics teacher) and he would have to read maybe 100.
They asked them all to give 3 college choices. We had an email to say there was a clash, He recommended our second choice as he said this has a higher acceptance rate for independent school applicants. Maybe it does, but we decided that what happens at a college level can be quite different to what happens in a subject level. So have decided to go for another college now.
That’s the only advice. DH went to uni in the UK and I came to the UK to study and we have MAs / MSc, but we were first-generation uni-goers and no family history of further education, let alone Oxbridge.