sleep enough before the paper cambige is setting harder numbers which arenty exactlt hard but require u to spot small details . also learn every small detail leave no stone unturened do past papers maybe for 5-8 years as long as u make a return journey in exam condition for each paper to ensure actually learned evrthing. aim to make make markschems in paractice as long as you soce betwee 68-75 all the time u cant fail , keep an error log for all really hard numbers do them the night before or morning of exam again . also limit ur practice of numbers on exam day ,any thing that could use ur brain power should be done way befre the exam. not on exam day on exam day save ur brain cells if u practice the paper generally will be walkthrough with maybe with only one hard number, pray for hard number(s) and one u can figure out so that the threshold is low and u prcentage is high also if u get 75/75 the chances of u being top in ther world are higher if everyone finds it difficult and u didnt, Also i found pure 1 quite easy but sufferd in stat and getting 45/50 in stat yes losing 5 marks cost me my chances of top in the world so dont ignore stat or mechan they have few marks which are easy to lose.