Tips and methods for \Revision and cramming. Actually mainly cramming for sciencey subjects. bio,chem,phys past papers vs learning which first priority when late in the game
Why are you 'considering revising last min'? Considering suggests that you have a choice, whether to revise last minute or not, the latter option is rarely a good idea.
I'm doing G484 and G485 too this summer and I also feel I've left it a bit late and am now having to resort to cramming. I would say focus on looking at mark schemes and learning definitions, some are guaranteed to come up and they're an easy couple of marks. Once you've done that, look through the papers to identify topics where they ask you to write long answers explaining something. Some topics (such as MRI scans, PET scans, evolution of the universe etc.) are frequently examined in this way and the mark schemes are usually quite similar. Learn how to answer these questions. Then make sure you know what all of the equations are used for and, if you have time, practise doing questions involving them.
Mate good luck with that, I'm doing the same subjects, all A2 + 1 physics resit, and even with three weeks straight of pure revision it's going to be a tight squeeze. Don't leave it that late if you have a choice.