You will have to look EVERYWHERE, all the time, and apply as much as you can. In september quite a lot of part-time jobs pop up because all the uni students leave and leave their jobs behind them - so I would concentrate on your exams now and then look everywhere.
Try garden centres, local shops, bakeries, applying online, look for hotels and restaurants that might want waiters and waitresses - most of the people I know with jobs work in waitress roles because they have quite a high turnover.
Don't be expecting a miracle though, the jobs market is very slow atm and it can take forever to get anywhere, I only recently managed to get my job despite searching since september last year. Don't be expecting loads of money either, as most part time jobs are minimum wage or close to it.
good luck!