Textbooks + Colour Coding = The ****
That's how I did it at the least. Write notes for a topic, leaving one page free after each page of notes (for questions and additions) and adding in small plastic colour thingies on the tips of the pages to associate the topics with the colours determined by the textbook.
If you use a lever arch and have loads of notes to take and put inside, i.e. literally fill it (first year at Sixth I did this) you will end up with the weight of the contents shunting the contents from the folder and causing it to sag. That's my experience, at the least.
If you are using textbooks, get good paper that doesn't bleed or feather, and if you are using lever arches, moderation for the amount of content xD