Cleared PMP in the first attempt with 4Proficient and 1Moderate. 

Preparation:

Initially started reading Head First (4th Edition) . Wrapped up the book in a week or two. But took a long hiatus before I gave the exam.

By the time I registered for the exam, version had changed from 4th to 5th. So relied entirely on PMBOK.Here are my tips.

1.) Read PMBOK thoroughly. All questions were contained within the PMBOK. 

2.) Try to understand the ITTOs rather than memorizing them. Focus more on Tools and Techniques that are unique to a particular process. 

3.) The PMI website has a question bank with 20 Mock tests of 50 questions each. That is a gold mine. I took about 10 tests from it. Helped me revise the entire PMBOK.

4.) Also take Oliver Lehman tests. Though questions were not of this difficulty level, this test will help u face situation based questions better. 

5.) Take your time to review your questions. Use the 'review' option in the test wisely.