Based on what I've seen:
1.
Taking control of your own learning.
That is, if there is something you don't understand, do something about as soon as you realise. Go to another textbook, ask friends/teachers/parents to explain, do extra homework until you understand it. Don't just wait for someone else to tell you what to do.
2.
Sucking up to teachers.
No, not really, but make sure you're friendly with them and feel comfortable asking them for help. Also, even if you don't need help, if they like you and sense that you really want to learn, they'll sometimes share tips or tell you extra stuff that the other kids didn't learn.
3.
Understanding *how* you learn.
This might be one of the most important ones. If you learn better by, say, drawing diagrams of relationships, then don't waste your time copying out formula after formula. It's really helpful if you even just do a simple google search for "ways to learn effectively" or "learner types" or something similar. Once you understand the best ways for you to learn, you don't have to waste your time doing less effective things - which means no 24/7 study
4.
"Exploit" your tasks.
Haha, I don't know how else to say it - that's my old English teacher's favourite phrase. I think this is pretty important too. Basically I mean read the assignment sheet and find out exactly what they want. If they want a feature article for the local newspaper, don't write an analytical essay. Write a feature article, with all the extras: be informal, talk to the audience, etc. Too many people (that I've seen anyway) just write the same thing regardless of what the task actually asked for - going back to the example, it might be a really brilliant analytical essay, but it's a terrible feature article. This also applies to those "terms" they use (discuss, explain, contrast, whatever).
Wow, I just read that and realised I sound kind of stuck up. I'm sorry, I don't mean to be
That's what I've seen the 'top' students at my school doing...I hope it helps you, somehow