What I do is study a week or so in advance just sorting all your papers and notes together. The subject you know you will struggle with the most focus on those the most. So I create like an outline (if your teacher gives review guides, follow that). Say math, I would take at least one question from each section we’ve done and try to solve it. If I know it then You’re good on that, if you don’t, then you should relearn or refresh your memory. Good luck! And remember there is such a thing as over studying so learn when’s your limit and balance time wisely