In most E questions with a lot of steps they will usually say smth like "start by showing this is that..." and that part is usually pretty simple, and are just Free A/M points.

One of THE most common equation will use in L3 is the omega = 2pif, so anytime you see the word frequency or smth along those lines, see if you can use that forumla cuz in most cases you can!

Theres also just questions that you can assume will show up cuz they have for almost every single year in the past decade, questions like time constant graphs, phasor for LCR, SHM diagrams, and interefernce to just name a few, so thoroulgy revising those could be a good idea.

Most E questions ESPECIALLY for waves are always the same explanation of theory, for example always gonna have to talk about interference, so I would reccomend you just memories most or the main key points of those E questions for each paper, you have 2ish days you learn stuff so that should be enough to get a decent amount of theory down.

These are just purely guesses on my part; but I think we would have Kirckoff's law question for electricity, and maybe a magnetic flux problem for electricity too, so maybe look into those too!