Dear Harry,
Cornelius is out of the office for a week or so, so let me reply to your post on top what John has already said.
First of all, there is no a universal recipe for preparation. Each person is different so are the preparation methods. However, based on what you say, you have taken only three simulated exams. There are eight exams in total (plus one ITTO). So you have five more to go. When I was preparing for my "real" exam, I practiced all of the simulated exams. I took one exam per day which usually took me about 3.5 hours to complete and the rest of the day I was spending analyzing my results. So it took me 4 weeks for practicing the exams (I practiced on weekends only) not including 2 months of reading PMBOK Guide, listening to the PrepCast, and reading one of the exam prep books. After completing each simulated exam, I was reviewing not only the incorrectly answered questions but also those that I answered correctly to make sure that I selected the correct answer "intelligently" rather than by a guess. Topics of the questions that I incorrectly answered or guessed, I studied more. Then I moved to the next exam hoping that its results will be better (which indeed were). Then, I moved to the next exam, and so on, until I reached the last one, exam #8, where I scored close to 90%. When I started, my 1st exam score was around 60%. I passed my real one with 4P and 1MP. So my system worked for me. Hopefully, you will find the one that works for you.
Hope it helps. Good luck with the rest of your preparations and definitely with your exam! Don't forget to post your lessons learned once you pass (and I'm sure you will)!
Regards,
Stan Po, MBA, PMP, PMI-ACP, CSM, CIPP
Product and Program Manager
OSP International LLC