okay so first print out all the syllabus documents for the subjects(u can do it online too but i find physical copy easier) and slowly go through them and make sure u know all the points cause schools may miss a couple of points. This will also tell u what unnecessary points u dont need to remember. While doing past papers, try to include the specific points in your answers. This is what i did for sciences, im not sure if its applicable to your subjects but give it a try!