Since I used this website the most of all my (few) online resources, I feel it's only fair to give something back.
The short story:
I had only one shot, I studied for one month and got 690. This is more than what I need. I am happy and it's all worked out for me. I could have got more, I know it, but I only had one shot.
1. By changing my routine and life for one month.
2. Past papers.
3. By focusing only on what matters, not on everything there is.
4. By using the 80/20 rule.
5. By killing myself with impossibly hard questions to make the tough ones easy in the actual test.
If you can't pass the GMAT to your satisfaction after using the above, I'd say you should get tuition for it. I've read that it really does help.
The long story:
I'm not going to go into deep detail, but I will say that the whole GMAT experience started out quite daunting. In my country, we don't usually have to pass these sort of tests. If you got an A at school and later a 4-year university degree, you are obviously clever enough to apply for an MBA. Clearly, Americans aren't like that. And clearly, the space is limited in their schools. So, onward with the GMAT, and I started by simply reading up on it. The stories were mainly about people saying how hard it was and how to study yourself into oblivion so that you can pass.
The worst part for me though, was that due to circumstances I won't go into, I only had one month to prepare.
I will admit that I have a maths aptitude higher than most, but the GMAT doesn't really test maths skills, its logic. So, after I read many blog posts and comments, and saved tens of links in my bookmarks on my Internet browser, I realised that the best way to study in one month was to focus on the valuable stuff. Just like at school and university, the best thing in the world for any exam is: past papers.
That, and the changing of my daily routine, are the main two GMAT tablets I needed. I did the following: No drinking or partying, sleeping well and studying regularly to a timetable. Regarding material, I bought only one book - the GMAT Review 13th Edition. The rest were all the practice exams online I could find. Next, I made sure to tackle incredibly difficult problems, to force myself to go the extra mile.
For me, it became (after the first week) my mission, my goal, it was everything. I stuck questions up on the fridge, I asked my wife if she could answer some questions, I explained the answers to her, I made up my own questions, I checked out the test venue, I phoned one week before and one day before to confirm everything, heck, I don't even remember everything I did to focus entirely on achieving my GMAT goal. It wasn't stress, it was absolute focus.
But once again the two tablets to mix with that focus: Complete as many past papers as you can, and learn from every wrong answer AND change your routine.
Good luck to everyone!