I have now taken 2 Prep tests and scored exactly 600 on them. My verbal is high but my quant is low and the largest reason behind this is DS. I can't for the life of me get comfortable with them. I have been working primarily from OG11 and the OG Purple and Green and DS is my one major problem. I get most of the DS problems from first 100 or so of these books but after that my hit rate drops dramatically. On the Prep tests they are about 80% of my missed questions. I see the right answers and it makes sense after seeing it but for some reason I can't get them conceptually before-hand. I'd like to know if anyone has any secrets or advice as far as DS and avodiing careless mistakes (for both PS and DS)?

On a side note: I score 600 and that is within the median 80% range for schools I am looking at but personally I know I can do better and want to do better. I'd really like to improve on the above area in order to make my GMAT appear above average for my target schools.

Thanks to all!