I got a 5 and didn’t start studying until a week before the exam!!!
Buy the crash course book and read through it until you get the content memorized. Keep reading and place sticky notes where the info is unclear. Drill those topics over and over and you will get a five. Review past FRQs. I did not do this, but the FRQs this year were very easy and I got lucky.
Watch Bozeman Science videos!!! These are perfect for FRQs because he gives examples! Do not just watch the videos through; pause after he completes vocabulary/concept and repeat vocab/concepts to yourself in your own words. This is key for retaining this information. Otherwise, if you just watch, you will retain very little.
Start in the beginning of the school year and it will be a breeze. If you wait until the last minute {like me}, it will still be doable, but much more intense. I recommend the former.
Good Luck!
Source: Scored a 5 on the 2017 Exam and used the Crash Course Book/Bozeman videos to study