Is this revision technique effective?

I'm aiming to get A grades in biology, chemistry, maths and English literature. For biology and chemistry I just read through the revision guide on the topic I'm studying making sure I understand everything I'm reading and asking questions on what I don't understand.

I then answer LOADS of questions on that topic until I know it inside out and continually revisit past topics and answer questions again.

I'm anxious if this a good method though as at GCSE I'd rewrite my notes, I hate rewriting my notes at A level, I find it frustrating writing out things I already know and it just makes me fall asleep, reading it doesn't.

By doing the reading & questions method, I've managed A's so far, so is it a good method?