Instead of choosing a random topic from the syllabus, you must break your preparation into sections. Sub-topics from each section should be selected and then strategy on clearing concepts must be made. Never leave any concepts doubtful or unsolved. Once done with the syllabus and concept clarity, you should move towards solving previous years papers. Give mock tests as much as possible. Time management is one more important thing you should look upon. Remember that practise will increase your efficiency. Use the books that you have studied in your undergraduate for the preparation. Along with this you can grab a book on Social Psychology by Baron and Bhardwaj, Organizational Behaviour by Baron and Greenberg. Beside this, regularly read articles, magazines, write ups about psychology.