I started my prep with PMP , ad ultimately took 6months to do it. Only to realize that the best srategy was to go for the kill - which is start backwards.
Simulate the exam with PMP simulator and understand the pattern once you have gone through 1 reading of book, or taken any course.
Practice Practice Practice! Once you have done the syllabus, exam practice is the key. Improve your scores, create a lessons learned sheet and revise.
I applied the same strategy for PMI-ACP and voila, it took me only 2 weeks to crack through it.
Hence lessons learned, create a timeline. create a strategy, stick to it. and you will be there.
All the best!