Lots of great advice here. I wonder if the opposition between 'academic-related' and 'job-related' interests is a bit of a false dichotomy? If I think of our students, many of what start out as subject-related interests (i.e. writing, journalism, book-reviewing, drama, music, running book clubs, tutoring younger students, setting up websites etc), become job-getting interests in the end. There is no 'formula' for what we are looking for - this is why we look at every single application on an individual basis.
I know it's really important to be honest about our high standards and the competition for places (especially if we are asking applicants to commit one of their UCAS spaces to us), but I wonder whether talking too much about 'stellar', 'exceptional', 'perfect' performance (at GCSE, AS, A2, or aptitude test) leads some students, especially from the state sector, to feel that this is all beyond them, and thus not to apply? Do you think that might be the case? It's very hard to find the balance on open days etc between being encouraging and being realistic.
Keble College provides very useful feedback on the admissions process, written by tutors (the ones for English are particularly candid and entertaining). I think what they say is applicable to most colleges and tutors.
www.keble.ox.ac.uk/admissions/undergraduate/subjects/past-feedback/