For sciences and geography, would really recommend seneca learning
There are some really good youtube videos on geography that I found super helpful (let me know if you want some of them linked), and people like freesciencelessons, hegartymaths on youtube are really good. And for Geography I just did lots of pop quizzes I made myself and did flashcards and mindmaps. Try and learn the case studies well, because they can help you understand a topic and get you lots of extra marks!
Latin grammar - biggest recommendation would be to just do a little big of practice as much as possible. I couldn't really find any good resources, so each night would just recite a different verb conjugation / learn some irregular verbs etc. Literally just 5 minutes for 2 or 3 evenings a week, and then when I did this I wrote myself a test, which I did a week later. Helped me to actually get it in my brain and remember it... But I know that everyone learns in different ways - this is what worked for me, but if it's not good for you try something else. Maybe flashcards? Lots of my friends used them!