Hi! I'm in S5 and taking highers too. I take higher business and English this year and got an A in both of them for nat 5. In my prelim for Business I got a C which i was so upset about and decided to lock in, Past papers was a big help for me and anything I got wrong I would reread the topic again, make flashcards for them and write notes over and over again until I got it right. For highers I plan to do the same thing but earlier so I can cover all the content as there is a lot this year. Make sure you are writing keywords too as they are the ones that get you the marks and if a question asks you for two points, write three detailed ones instead, to have a higher chance to get full marks. For English, quizlet was a big help, flashcards for my quotes and a dictionary to find out the meaning of words. For RUAE do flashcards for your techniques. Write essays and get your teacher to mark them and give you feedback till you have perfected it. Hope this helps! I didn't take the rest and for maths I got a B but this year i will watch this guy on youtube- clelland maths and focus on weak areas and practice questions frequently.