aim to practice everyday, you dont have to do loads, maybe corbett maths 5 a day (its good bc u can choose the level of questions). if u don’t understand a topic, i recommend GCSEmathstutor on youtube, but his videos are quite long so i always change the speed of the vid to save time. for maths dont waste time on making notes for everything, but i do find it helpful to have a book w ‘methods’ e.g. solving quadratic inequalities. try igcse papers, the questions are similar to what is at the back of the gcse papers so u will get rly good at those. sometimes mark schemes can be hard to decipher, so maybe look for papers with model answers (i think PMT has some). obv u need loadsss of practice, but dont just practice topic content, make sure u know how to problem solve. the IMC questions are good for these bc often u dont need actual revision, u can just use it to improve ur skills. a revision guide is useful (CGP is good) to revisit topics and making sure that uve covered everything + saves u from making notes.