Summary: If I had one tip for the GMAT taker, it would be USE GMAT CLUB. Period. So much information is available and if you use it critically you have all the external tools for success. I have no doubt someone could just use the questions discussions and rock it for $0 in prep materials. Also gives you faith in the human spirit that people are willing to help.
My second tip would be, work smart, not hard. After reviewing a million GMAT club question discussions, I saw that the hardest Qs REQUIRE working smart. Hacking through a problem (ie writing out every iteration in a combination problem by hand, or using a formula when doing it by hand reveals a shortcut), even if you get it right, should be recorded as an error because you are likely working more slowly than you could. Likewise, when you see an answer explanation using an excel spreadsheet, just skip it. Either the answerer is missing the point, or the question is not well written and isn't worth your time. (Or the answerer is trying to put to rest an endless discussion, good but just not useful to you).
Prep materials: All of OG12,
Manhattan GMAT Number Properties, Kaplan Prime, Kaplan Math, and Kaplan Advanced. I used
MGMAT SC for idioms and the question bank. I felt that the reviews of these materials here were accurate.
Manhattan GMAT CAT tests (they come with any book) were the best single resource because the questions can get wicked and the analysis is super helpful. Kaplan Advanced is relatively brief to work through but you get good bang for your $ and I think it's kinda funny (yes, I have cracked).
I also worked through the free GMAT Club materials including several of the lists of questions. Some of these questions are great, and some are just not well written. Similarly, with the verbal (not just GMAT club, in general), I think some of those answers are just made up, they are so ridiculous, and personally I will never understand them so I didn't waste sleep over it.. well OK sometimes I did, but I shouldn't have.
Prep method: In a quirk of fate I took 3 months leave from my job in September so I had a lot of time to study. I got my math skills basically straight, then hit the practice tests, using the other questions for warmup. On my first timed practice set, I panicked and bombed. On my first whole practice test I got really bored and bombed verbal. This is why I did at least 8 practice tests with AWA to build up my mental stamina and get used to the timing. I did 14 practice tests total (mostly Kaplan,
MGMAT). In addition to getting my timing straight, doing CAT tests gives you a shot at seeing harder questions. My battle was finding enough truly hard questions to practice in a timed setting and this helped.
Timing: My timing ended up OK but I still had the FEAR so I kept the timer visible at all times and recalculated time remaining every 3rd question or so. It's theoretically a waste of time but it kept me calm.
Pre-test hours: I just thought about anything BUT GMAT and spent pre-test time looking at Cyber Monday deals online.
Test time: No big shocker about the location or setup, except fiddling with the headset, pen, laminate board, etc. Left handed people like myself can expect to smear ink all over the darn place. I felt like the keyboard was weird and it threw off my writing but whatever. Also there was a guy with Tourette's in my test room which paradoxically kept things mellow (it wasn't like a cussing thing, more of a grunting thing).
Math: Seemed a little easier than I had faced before, which gave me doubt, but I just kept telling myself "you are rocking it... the easy questions must be experimental". Question mix was what I expected from the practice tests.
Verbal: Usually my strong point, but about 5 minutes in, my mind went AWOL as I tried to pin down how math had went. From the practice tests I knew to expect this feeling so I buckled down and told myself this is where I can pick up the relatively easy points. Verbal seemed fairly similar to my prep work, meaning there were more than a few questions that were just picky and stupid and pointless. Yes, I hate verbal.
The Aftermath: Grinned like an idiot. Bragged about myself to my parents. Etc., etc. It was 2 days ago and it still hasn't sunk in yet. I guess my dreams of Bschool could be a reality...or at least the GMAT is no longer standing in the way. I have nothing but thanks for everyone in the GMAT Club community, the generosity that people have shown with their time and efforts really, truly has improved this experience for many.