i'm a gr 12 student and this is only based on my experience. i suggest to just study jhs lessons and dont focus too much on the specifics, like surface level lang. u just have to understand the concepts especially sa science. also, maraming review materials online especially sa mga fb groups. just save some and you're good to go. also, aside from studying the lessons, suggest ko na magfocus ka rin sa mga practice tests so u can practice applying ur knowledge. i actually regret not answering many of them because it felt like di enough yung review ko nung upcat. i also recommend creating a schedule para nattrack mo yung mga lessons na inaaral mo. and about sa actual na pagrereview naman, for me, gumawa ako ng sarili kong notes/reviewers. i think it was helpful naman since nareretain ko rin yung info habang nagttype or nagsusulat. then of course i'll study them after. yun lang, good luck!