I got straight 9s by doing this: Rewriting notes from class (reading textbooks is helpful especially since sometimes it’ll have those extra details in there your school may not have covered), if I didn’t understand a concept watch a few YouTube videos, did active recall on every topic (so I’d split a unit into 5 sub themes within it, random spinner to pick one, write everything I know down, reread notes and add any parts I missed, repeat for everything else). Did lots of past paper questions and marked them, asked teachers if really didn’t get something. Your method should work as you’re learning content and practising but I’d recommend adding some recall cause you can look at a piece of text and think ‘Yeah I know this’ but actually you’re just familiar with it and remember learning about it.
I never did any of those big full topic videos (although there weren’t any for my exam board), but I’d recommend if you do those to watch 1 at the start of revision for a recap, and then 1 maybe a week/5 days before exam, since by then it’s more important to practise.
Hope this helps!