The only thing I would recommend for last few days before CAT would be being positive & confident and not studying overboard, just few revisions and you are done. Going through notes,formula books and few previously solved mocks is what all needed. Adjusting body schedule according to exam day is helpful but not mandatory. Something which people might not tell you but in my opinion it is most important, that is not having too much involvement with fellow CAT aspirants and social media to keep negativity at bay.
The list of things you should not do is long which includes watching too many CAT motivational,success/failure stories,strategies videos. Even one should not engage much in one shot videos or probable question's gamble, all these content creates a pressure on the student. Just revising whatever is already covered and spending time with loved ones or practicing anything that makes one happy should be done.
Speaking from personal expirence,the most important thing on D-day is keeping calm and acting up the strategy that suits the paper best and not your pre-defined strategy.
