How to raise grades significantly before exams??

Hello, I'm currently in my final year of A Levels and I'm studying Sociology, Psychology, and English combined.

I was wondering if any current or past a level students have managed to raise their grades by a great deal in order to match their predicted grades?

I'm predicted ABB but fear I'm only capable of around BBC, having only achieved ABC and BBC in the past two sets of mock assessments. Is achieving ABB or even higher a possibility? If anyone has managed to do this in such a short space of time before the real exams, teach me your ways!! I honestly do not know what I'll do with myself should I not achieve what I want/need.

Also, any psychology tips would be useful seeing as that is my weakest area!!



Thank you!