The best thing you can do is get a prep guide, review some of the most common strategies (such as common grammatical errors, common types of math problems, how to do data sufficiency, etc.), and get practicing on the Official Guide.

Remember that with such limited time, you should only focus on topics that come up a lot. There's no point wasting a day of study on, say, advanced permutations and combinations since you're unlikely to even see one question on that.

I was in a similar situation, though I've been studying for the last few months. My practice scores ranged from 500-640. I am aiming for at least 650.

I was scheduled to take the test today. About a week ago with an absolute free schedule, I tried to cram as much as possible by reenforcing my foundation and targeting my weaknesses. To measure my last minute efforts, I did a GMAT Prep practice test 2 days prior to test date and scored 600, so I cancelled my appointment - didn't want to chance it.

However, in my efforts to cram and build on my foundation - I did see a bump on my SC and CR as I spent time on these in my last week. If you are a native english speaker, I would focus on this in the last week, as you can potentially see a slight bump on verbal with some effort. On math, I don't know exactly what I did, but I did score higher on my practice test. Rereading the math section of OG over and over again instead of trying to solve each questions for the 4th time, helped me out in reviewing the concepts.

Also, when I did research on how to study in the few days prior to test date (via BTG), I found 2 main points: 1) some ppl took multiple practice tests their last week to build stamina and to guage their performance 2) some ppl reread all their notes, reread OG, and did some practice tests but not alot.

I did a little bit of both. I took practice tests during the last few days (in a row), but realized my score wasn't inching by much. So I switched it up and decided to just reread OG over and over again...waited about 4 days, and saw a slight bump, but not more than the highest score that I took. Anyway, take this for what its worth. The only material that really helped me was OG 11 and rereading the explanations over and over again to get the underlying concepts.

thanks a lot ... you didn't tell me about Verbal Strategy... shall I stick to OG for that too

Yes, stick with OG on verbal if you are down to your last few days.

For CR, I turned to the explanation section of the book and covered the explanation with paper and read the argument. In my own words, I tried to describe the situation or rephrase what I thought the argument was all about, then uncovered the situtaion explanation to match up my rephrase - this helped me exercise my line of thinking to be inline with gmat's way of thinking. Then pick you answer choice and in your own words describe the reasons why you picked your answer choice. Then uncover the reasoning explanation in the book to see how your line of thinking matched up. After doing about 10-15 in a row, you'll start understanding how they reason and what you need to do to tweak your way of thinking.

For SC, just go through those questions by covering the explanation and making your pick. Then uncover the explantion to see how you matched up and read ALL of the explanations to make sure you got the question right and for the right reasons. Make notes so you can commit some grammer rules to memory.

For RC, it really depends on what kind of reader you are. For me, it helped to skim the passage and get the general idea. When it came to big picture type of questions, I was able to answer them bc I got the bottomline of the passage. Though on questions that were specific and required the reader to go back to the passage, I would reread the relevent section to look up the answer. Anyway, whatever RC strategy you choose will depend on what kinda reader you are - if you are active or passive. I tend to be a passive reader, so the only way I was able to combat that was to get the bottomline and go back if needed. Some ppl don't recommend this bc you lose time, but I made sure not to spend to much time on rereading....anyway good luck!

Yes, stick with OG on verbal if you are down to your last few days.

For CR, I turned to the explanation section of the book and covered the explanation with paper and read the argument. In my own words, I tried to describe the situation or rephrase what I thought the argument was all about, then uncovered the situtaion explanation to match up my rephrase - this helped me exercise my line of thinking to be inline with gmat's way of thinking. Then pick you answer choice and in your own words describe the reasons why you picked your answer choice. Then uncover the reasoning explanation in the book to see how your line of thinking matched up. After doing about 10-15 in a row, you'll start understanding how they reason and what you need to do to tweak your way of thinking.

For SC, just go through those questions by covering the explanation and making your pick. Then uncover the explantion to see how you matched up and read ALL of the explanations to make sure you got the question right and for the right reasons. Make notes so you can commit some grammer rules to memory.

For RC, it really depends on what kind of reader you are. For me, it helped to skim the passage and get the general idea. When it came to big picture type of questions, I was able to answer them bc I got the bottomline of the passage. Though on questions that were specific and required the reader to go back to the passage, I would reread the relevent section to look up the answer. Anyway, whatever RC strategy you choose will depend on what kinda reader you are - if you are active or passive. I tend to be a passive reader, so the only way I was able to combat that was to get the bottomline and go back if needed. Some ppl don't recommend this bc you lose time, but I made sure not to spend to much time on rereading....anyway good luck!