You need to know your syllabus and understand the exam pattern. There is no negative marking for few set of questions. This means,  there will be no negative marking in the 15 alternative questions. The candidates have to attempt 75 questions out of 90  or 25 out of questions 30 in each section of Chemistry, Physics and Mathematics.  Though the syllabus was speculated to be revised and reduced, no official information has been released about it. You can check the syllabus available in our article: https://engineering.careers360.com/articles/jee-main-syllabus Make a plan and stick to it. Make a note of the books to refer from and practise as many mock tests or sample papers as you can. Divide the syllabus into Class 11 and Class 12 and the topics as "Need to Learn", "Weak" and "Strong". Now it is important to check the weightage of each topic. In Physics, Modern Physics take the top slot with 5 questions. Heat and Thermodynamics, Optics, Current Electricity, Elcetrostatics get 3 questions each. Magnetic has 2 questions and the rest get 1 question each. In Chemistry, Transition Elements and Coordination Chemistry, Periodic Table and Representative elements take 3 questions slot. Thermodynamics and Gaseous state, Atomic structure, Chemical Bonding, Chemical and Iconic Equilibrium, Solid State and Surface Chemistry and Nuclear Chemistry and Environment get 2 questions slot eacch and the remaining get 1 question each.In Mathematics, Co-ordinate Geometry gets 5 questions. Limits, Continuity and Differentiability, Integral Calculus get 3 questions slot each. The rest get 2 and 1 questions slot. For complete breakdown, please read our article: https://engineering.careers360.com/articles/jee-main-syllabus-weightage . Once you complete a topic, try to practise the concepts and write down the important points and paste them somewhere that you can see. Practise questions from that topic