Alright here's what I have learned in my 3 attempts; pardon me if it sounds boring.
One, Stay cool, calm and composed, don't panic even if you don't know the answer. Two, Be rational while presenting arguments, no emotive talk. Citing facts and incisive analysis will do.
Three, Stick to relevant points, avoid irrelevancy just for the sake of prolonging the answer.
Four, Keep yourself motivated, attempting back-to-back papers is an arduous task, therefore keep pushing your limits, one can always relax once exam is over.
That sums it up I think, best of luck to all the candidates.

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