Here's some things I found useful.
a) Don't just go after finishing a lot of material. Use the
OG's they are the best guide and the closest to the actual test. Get the 11th ed. and if possible get the old one too. That makes up for a total of 2200 questions. That's quite a lot.
b) Devote at least some time everyday. Even when I did not have enough time, I still made sure that I would practice for a minimum of 1hr, even if it meant sleeping an hr less. I don't like breaks in preparation. I don't know about you but it helps in keeping focus over a period of time.
c) Princeton is ok for a preliminary strategy for POE and the AC/BDE for DS. Make sure you spend a week brushing up some GMAT grammar ( Manhattan's gmat and peterson's verbal grammar prep sections were quite useful for me. If you want to get just one, get the manhattan verbal guide)
d) Mark all your answers in a piece of paper and as you solve just put a tick or a check next to questions that you spent more time or found tricky. The idea is that you should be able to look back at the sheet just days before the exam and do a quick run through questions you got wrong.
e) For RC's I actually found it worth the while to read the full passage. It's easier that way to get the correct answer. All the princeton POE etc. is just a waste of time and not practical for RC's in my opinion. The same hold for manhattan's rc strategy. You will waste more time than gain anything.
f) Always use a stop watch even while you practice. It pays to practice as you will eventaully take the exam.
Cheers and all the best for your prep.