Figure where you are losing your marks on exams.
For me, I'm incredibly strong on all of organic chem, reaction pathways, catalysts, and theory; I arrogantly and shamelessly know it all.
My only falling point in these realms is instrumentation, I'm still a bit iffy on things like multiplets in high res H NMR but I'm trying to knock that all out today.
Otherwise, I'm pretty damn weak with AAS, AES, and UV-Vis. Spectroscopy, frankly, sucks. So that's where I'm putting all my effort,as it's where I lose all my marks (in multiple choice AND in SA)
Figure out your weak spots and learn them. Don't bother writing pointless notes, however, of the things you know (for instance, I know all too well what a paper/TLC chromatogram looks like, so labelling it and drawing it well is time costly and tedious and doesn't teach me anything)
As well as this, it comes down to silly mistakes; doubling instead of halving a calculation because of a molar ratio, etc. These are unavoidable and you can only practise them.
Also, figure out your exam technique; how are you going to do the exam? For me, I always jump straight to SA and finish it within an hour usually, spend the next 10 minutes re-reading it and looking over it, and then I go to multi choice, get all the easy theoretical ones, and leave the excess reactant/calculation/finding the correct oxidation number questions to last
Half a rant to alleviate stress, half constructive examples.