What do you do when you're tired or can't be bothered or lazy?
I'm not going to claim to be the high achiever you're looking for, but I've done a lot of study over the years, including through completing medical school. Hopefully you'll find this post useful, it'll take a different line of tact from the others.
You can read all about how everyone else studies, as above or in the numerous other threads on studying on this forum over the years, and you'll notice one thing - they're all different. No two people study the same way. Some people take small breaks, others large breaks, some people make lists, others use timetables, some people study at home, others in the library, some people drink caffeinated beverages, others don't. It's a mixed bag, and that's because studying is so very personal.
I think the most important question is in regard to the part I have quoted. That question is: why do you feel tired or lazy or cbs?
That sounds like an easy question on the surface, but the more you think about it and reflect on studying in the past year, the more complicated it becomes. Indeed, I'd be surprised if you could genuinely pin it down to only one or two things. I strongly encourage you to take the time to reflect on what went right and what went wrong in your studying this year. And I know many students start to roll their eyes at the mere mention of "reflection", but hear me out, it has merit. Make a list of your reflections, a physical list. Edit that list every day for a week until you've come up with a comprehensive list of what it is you did well and not so well in terms of studying/results/etc. for each subject. Only once you have identified all these issues, it will be easy enough to fill in the gaps.
For example, perhaps you realise after reflection that doing textbook questions for VCE physics did not help you to do better. How can you change this? How can you find what will help? Perhaps questions themselves are not useful, or perhaps you need more SAC/exam style questions to do instead, or perhaps you need to invest more time in making a cheat sheet instead, or perhaps... you get the idea.
Another example, say you get bored while writing an English essay, a completely rational response to writing an essay on a book you don't like. How can you change this? How can you find what will help? Perhaps you have too much excitement around you to focus on the essay (e.g. facebook) and a duller place to study might make the essay comparatively interesting, perhaps writing a whole essay at once is too taxing and maybe writing detailed plans with quotes or just introductions might be more productive for now, perhaps studying later in the evening when your mind is more at ease might help, perhaps it's boring because you don't have a solid grasp of the text and the confidence to do well (i.e. your 'boredom' is just an insecurity, not at all uncommon) and you need to understand the text in more depth, perhaps... you get the idea again.
A final example, perhaps you just can't do a solid hour of study for anything despite the dullest of environments. How can you change this? How can you find what will help? Perhaps a solid hour of study isn't how you learn (and that's ok!) and you need to break your study up into 30 minute blocks, or perhaps you need to set yourself mini-goals (e.g. a page of maths questions and then a break), or perhaps you need incentives (e.g. do a page of questions and then you can play that next Angry Birds level or whatever you youngsters are into these days), or perhaps you've done too much study recently and need a break (I always took Fri nights off), or perhaps... again, hopefully this makes sense now.
Indeed, coming up with those solutions will require you to read and listen to others. That's how ideas will come, and I implore you to search the forum broadly and pour over all the threads that address studying techniques. Threads from as far back as 2009 are just as relevant as those posts above me here. All advice is good advice when you're stuck. Pick and choose what you like, but pick and choose them in relation to
your pros and cons list. That's something I've found particularly useful during VCE and medical school.
Good luck