Honestly my no.1 was to stay away from people who used to say “ sab kuch parhlia, 5th revision chalri hai and all” but you should believe in yourself and your preparation and trust that everything will go in your favour
Also few tips that helped me:
Stay hydrated and eat healthy food it helps your body to function properly and work in stressful situations for longer hours.
Eat dry fruits they are brain super foods.
Stick to one single book throughout the year and study only that book before the exam.
Teaching your fellow mates its a very underrated technique but actually helps to retain.
Hope it helps!!
The only thing i used to say to myself before exams: “Hojaye ga, tension na ly hojaye ga, Kuch na kuch to kr hi lega”. I just used to remind myself that exam days will eventually pass-by and there is no point in dwelling over it.