Take mock tests and solve previous year's question papers - Solving previous year question papers of JEE Main and taking mock tests is extremely important to get a good rank in the exam.
Clear your doubts - No matter how big or small your doubt is, get them cleared. Reach out to your teachers, friends, and even mentors to ensure none of your doubts related to the exam remains unsolved.
Make a revision checklist - Ensure you make a checklist of JEE Main syllabus with the list of topics/units against each subject. Tick off the important topics as and when you are done with revising the particular topic.
Flashcards - Have a large stack of flashcards handy. It should contain all the important JEE Mains formulas, concepts, and diagrams. These could also be used in the last minutes before JEE Main.
Strengthen your weak areas - Every time you take a mock test, evaluate your paper and jot down your mistakes and weak areas. Work on the subjects, topics, and units in which you are weak.
Subject-wise revision plan - Making a revision plan will help you tighten all the loose ends. It will also help you allocate an equal amount of time to three subjects.
Summarise each chapter - Jot down the highlights of every chapter of each subject of JEE Main. You can easily access them whenever you want.
Decide the order of subjects - Find out the subject you are most comfortable with and decide the order in which you would attempt these subjects in the exam.
Continue with mock tests - JEE Main aspirants should keep taking mock tests at regular intervals all through the year. The frequency should increase in the last few months before the exam.