You need to know your syllabus and understand the exam pattern. 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. We also have JEE Knockout package for your preparation: https://learn.careers360.com/knockout-jee-main-april/

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. Refer to books like:

Concepts of Physics by HC Verma

Fundamentals of Physics by Halliday, Resnick and Walker

Understanding Physics by DC Pandey

Problems in General Physics by I.E.Irodov

Understanding Physics by Freedman and Young

Problems and Solution of Physics by Shasti Bhushan Tiwari

Chemistry:

NCERT Books

Modern Approach to Chemical Calculations by R.C Mukherjee

Organic Chemistry by OP Tandon

Concept of Physical Chemistry by P Bahadur

Concise Inorganic Chemistry by J D Lee

Physical Chemistry by P.W Atkins

Organic Chemistry by Morrison and Boyd

Mathematics:

Objective Mathematics by RD Sharma

Plane Trigonometry by SL Loney

The Elements of Coordinate Geometry by SL Loney

Algebra by Dr. SK Goyal Arihant Publications

Play with Graphs by Amit M Agarwal

Differential Calculus by Amit M Agarwal

Integral Calculus by Amit M Agarwal

Integral Calculus by Amit M Agarwal

Complete Mathematics for JEE Main TMH