A few of my friends were Institute toppers and I asked them about their study method. Most of my topper friends study just 2 days before exams in the library and then teach their friends and clear their doubts. 

Another topper friend solved all the previous year question papers of the subject and uploads the solutions on the Facebook group a day before the exam. She never missed any class, had great handwriting and prepared great notes. 

So basically, toppers , prepare for the exams way before most of us even begin. They are kind, selfless and are ready to help anyone who is unable to cope up.

Ultimately, every student has his unique way of studying.