I'd disagree about verbal.
If RC is your weakness, then I agree you can't do much in 1 week.
However, if CR or SC is your weak area, then you can do A LOT in 1 week. I brought my SC hit rate up from ~33 % to ~70%, and increased my verbal from 41 to 44. I know that doesn't sound like much, but its a good amount in terms of percentile.
For Quant, like the poster above said, identify a few weak areas and strengthen them.
I believe that if anyone is scoring below a 46-48 raw on the quant, that means they should focus more on the core principles behind the math questions, and not on tricks/strategies (assuming you're aiming for a 48+). After you get to 48+ then its more about practicing your timing/strategies/tips to help you go from 48 to 50/51.
Good luck