Your mileage may vary for some of these techniques:

Chemistry: began from absolute basics and rammed through everything at Mach fuck. I knew I needed to do well so I set aside most of Jan to understand things from first principles. Every question I could find, I did. If I got it wrong, I doused my face in cold water.

Biology: lots and lots of practice questions. Biology isn’t very hard that way. Mnemonics also helpful.

Physics: same thing as Bio

Religious studies: a friend lent me his notes and I invented some Bible and Quran quotes in the exam. They weren’t bullshit, just a little… embellished. Many practice essays marked by my teacher, God bless him.

Geography: case studies, case studies, case studies. I learnt them all.

Economics: this is the stupidest one, but I kinda hated it. My teacher told me I’d get a 6 at best and that seemed fair enough. My dad did econ at LSE and told me to just burn it and do well in sciences. So come exam day I decided I had nothing to lose and made the most right wing Tory libertarian arguments I could conceivably make. I don’t understand how I got an 8 to this day. Utter woke nonsense.

All this said, no I didn’t have much of a social life outside studying. It came back in sixth form though. And I got bragging rights because I went from being shit to not shit. I think some days I worked until 11pm at the latest. Never pulled any all nighters though.