If you are planning on typing all your notes, the best formatting strategy is the learn a variety of keyboard shortcuts (Crtl+B for BOLD). What you could also do is keep the kerning on the words very narrow and have very small margins. It is very common for people to have pages and pages of notes, with a lot of wasted space, hence the best stmway to effectively use typed notes is to make them very condensed. That way you can summarise for e.g. a whole module in depth within 4-5 printed pages.
At the end of the day, the HSC is a written examination bar Science Extension. Therefore, it is best to sit down and write your notes.
If you already have a set of unformatted notes, use tables for each different heading and do quick copy/pasting.
Going through a whole courses notes and fixing the text will waste your time.
Otherwise, if you are really into formatted notes, private message me, I can provide you with a set of notes, etc.