Formulate a study strategy; Get acquainted with the exam details
Strategy: As suggested by exam toppers, it is important to plan and formulate a preparation strategy. For this, look at your strengths and weaknesses, decide your number of study hours, arrange practice sources, and follow-up.
Exam Details: Aspirants are advised to understand all the nuances of the exam, ie. syllabus, pattern, model papers, number of aspirants/colleges, nature of questions etc.
All exam toppers and experts suggest aspirants to allot at least 2 months exclusively for revision. This will help you retain all that you've learned all this while, for the final test day, and will also help calm your nerves.
What a lot of JEE aspirants tend to do is that they overlook their preparation for the Boards exams. However, as suggested by experts and toppers, Boards are crucial for building your conceptual base. Thus, always balance your preparation for the Boards and JEE exam.