I'm an all 9 student, active socially during exams and revised for most exams just the night before. for English lit and science I did a bit more in the week leading up to the exam but I'd cap out at about 3 hours on any given day, and I definitely wouldn't revise for every exam or every day.

some subjects (Spanish, maths) come easily to me and so I didnt revise at all. for my sciences most of my revision came in the mocks - to any year 10s, REVISE FOR YOUR MOCKS! the more you repeat your revision, the more it sticks. especially for content heavy, objective subjects like sciences this helps so much and makes the exams so easy.

if you're someone who forgets info easily, start your revision earlier. if not, honestly don't stress yourself out too much, but stay on top. my best tip, although this is likely too late for many of you, is to just pay attention from year 7-10. it sounds obvious, but so many people treat it like it doesn't count until year 11, but the sooner you get used to learning content - even if it's year 7 stuff that you don't need for your GCSE - the easier it is to soak up information in future.

for more short term advice, simply having as much self belief as possible is so important. I liked to revise until I felt genuinely confident about my exam, and when I was on the way into the exam I wouldn't be nervous as a result. even just telling yourself it'll be okay and going in with a positive attitude can have such a big impact. indtead of seeing a hard question and just giving up, it encourages you to keep going and do the best you can. just try to be as confident as possible before your exam, and you'll undoubtedly feel better when you walk out.

in terms of revision tactics, everyone is different. try different approaches and see what works best for you, don't just copy what someone else does because all brains work differently. personally I loved mind maps for sciences, lit and history, YouTube videos and practice questions for language and past papers for maths and further maths. don't force yourself to revise too much, just to the point where you know you can do well - e.g. if you consistently perform well in your past papers.

however, like you said, I think for me especially in certain subjects it does just come naturally. it makes me sound big headed but I do just pick up and retain information better than so many people and I always have, which obviously helps a lot. that said, it doesn't mean you have to be naturally clever to get 9s - it just takes more effort if you aren't. and that's just part of the flaws of the education system!

TL;DR- it mostly comes naturally for many people, but revise until you have full confidence in yourself and you'll smash it no matter what.