1.Material Collection

Syllabus
All the relevant books based on the subject(Divide the books in two groups - (1) Fundamental and basic concepts (2) Problem oriented
Some books helpful for pre-requisite knowledge on the subject
Some good guide books for GATE
Previous questions papers
2.Keep contact with some expert and GATE experienced persons
3.Study - Syllabus and Previous questions papers

4.Start from the first chapter

read at least 5 books, it will widen your knowledge(if necessary consult with the books for pre-requisite knowledge or with some expert)
Note down the probable concepts(definitions, unit, dimension etc.)
Note down necessary theories, formulae etc
Solve problems as maximum as possible(from text books, Guide books etc)
Think about various tricks in solving problems(if necessary, note it)
Go for series of self tests based on this chapter(take other's help to conduct tests)
Continue the self tests until getting a very good score
5.Solve more and more problems, discover more and more new tricks…
6.Follow the same procedure for the rest chapters

7.Finally, go for self tests based on whole syllabus(take other's help to conduct these tests)

8.On the exam day…you will be at the Pick, who can stop you?