For CR I did not do anything special. After a certain point in time one starts recognizing patterns. Infact I regret that I did not go thru the Powerscore's GMAT CR Bible which some recommend. To ensure that one is 100% prepared for CR, I think it might be good if you could go through this book. Ofcourse for the types for questions and approaches I relied on Manhattan RC
/CR book but similar concepts can be found in other books as well. I did peek into Powerscore LSAT Bible which was uploaded by one of the members and the material looked good.
For RC, I was miserable too. But surprisingly towards the end my RC improved significantly to the extent that I was making very few mistakes. I guess what helped most was to review the questions one gets wrong and understand what led one to choose a particular choice. Quiet often we choose an answer based on instinct. That should be avoided at all costs.
if it is a detailed questions, pl. ensure that you read the relevant paragraph before answering even if you might think that you know the answer. I managed to avoid a few silly mistakes by doing this. Also for bigger paras, I also tried to paraphrase but trust me it is not easy to paraphrase as well one can possible do in a mock exam in the actual exam owing to time pressure and partly owing to the crappy superfine pen and scratch paper. But it does help a little to paraphrase a few words to get the gist of the paragraph for bigger RCs. For smaller RCs, ensure that you read and understand the RC the first time you read it. This makes it easier for you to reply the questions once you are through with the reading.
Thanks mate for answering my questions so patiently....