One can make Science strong by following these steps:
Read the entire chapter from the NCERT textbook thoroughly.If it is difficult, divide into sections and take notes as soon as you complete one section. Complete the rest similarly.
Practice questions related to it.
Revise all the topics given in the syllabus from time to time.
Practice all the problems and solutions in the in-text, do the end-text exercises and browse through the summary. Study regularly without fail.
Attempt mock tests to get a good command of the various topics and get an excellent score.