Does anyone have any good ideas for jobs for pre university students.?

I live in england and I am in dire need of a job before I go off to uni. Does anyone have any good ideas? I have been searching the internet for hours now and I think i'm starting to lose my mind! I looked up all the supermarkets (waitrose etc) but the best they could come up with was a early morning shift from 3:30 am to 7:30 am in Croxley. Please help!