Well for Econ: If u have nailed the 2 and 4 markers then focus on the 6 and 8 markers cuz they are the difference between an A and an A* ( the more points u can score on them the better).

Brian Kemp is good for summarizing concepts and Jacob Clifford is good for explaining Econ concepts. Meanwhile, Economics Explained is great at helping u understand Economics in the real world ( idk how much u would find EE to directly be useful to ur studies, it depends on how much of videos make sense, but the guy's got a GREAT channel aside from trynna learn for an exam).

Answering in Econ is like writing a persuasive essay in English so ensure ur English helps you:) Sometimes the textbook is WAAY too long so revision textbooks do the trick, give u enough info to refresh and consolidate your memory but not too much that u get lost and overwhelmed or fixated on the little details. I had 3 revision guides by the way. I found out that the one by Colin Bamford was the most useful for me. Get your answers marked by a teacher as much as possible ( same goes for Business). Use Econ jargon properly. Jargon gets u sum marks. ( Same goes for Business).

Meanwhile for Buisness: Practice ALOT of 8-12 markers, you must already be good at the 2,4,6 markers. The former is 50% of your grade so u wouldn't want that to go to waste. Brian Kemp is also good for Buisness and there are other channels like Sense Buisness studies ( see if u like them, cuz I didn't).

Be thorough on everything and study efficiently ( if u know u aren't so good at something, work on it more). The reasoning is that Buisness is a small syllabus with MANY arbitrary facts, not many of them matter in the grand scheme of things so u gotta make your studying count. Heck, for the IGCSE exam, if it helps you to study more efficiently make a contents checklist ( I did) and a past paper checklist. Even if your teacher goes over a topic a thousand times and ur confident in it now, trust me paying attention will be worth it cuz at some point u will forget everything.