Essay-based subjects: how to improve writing technique?

i also did english and history at gcse! they were my best subjects as i got 9s in them (doing them for a level too). maybe someone else can help you with geography, but these are my personal tips that worked for me.
firstly you need to understand that history and english are vastly different, and therefore the essay structure for both is also completely different. with english, the mark scheme is very subjective- i believe the word "flair" even appeared on it with the exam board i used, which means you need to focus a lot on use of vocabulary and stuff like that (e.g. using a thousand different synonyms for "shows" like accentuates, further intensified, etc). on the other hand, with history you get NO extra marks for the "fanciness" (for lack of better word), and therefore do not waste your time with it.
for history, the absolute rule was to write and introduction, three main body paragraphs, and a conclusion. do not write less than three- you will have not written enough. also do not write more than three- you will run out of time. the key thing for time management is PLANNING. a lot of people think this wastes time, but it really makes or breaks an essay. having a rough guide for what you're going to write will save you time while you write. also as basic as it may seem, PEEL works better than any other paragraph structure. make a point, then show off your historical knowledge and provide evidence, then explain why/how this evidence is important/relevant, and then link it to your point (which should be relevant to your over-arching thesis).
english is very broad. you have to adjust your writing to be different for poetry, prose, drama, etc. also the exam board i used for english was WJEC which i feel is quite obscure, and potentially different to yours. honestly the best thing to understand english essays is just keep doing them and get your teachers to mark them (do not ask ai to, please). then write another one with improvement. it's still october so if you keep doing this till may, you're sorted.
for timing, the only thing you can do is practise unfortunately. if you get set an essay for homework, do it under timed conditions. this may mean you get a lower mark than your friends- it does not matter. only the final grades matter. the more you practise, the faster you'll get.
good luck!

The essay-based subjects I'm doing are English, Geography and History for GCSE. Are there any tips for how I can improve my writing technique and write quickly within a time limit?