Taking notes on Critical Reasoning?

Note taking is indeed a time consuming method and while it may work for some candidates for some others it doesn't. Your focus while doing a critical reasoning question should be to understand the meaning of the argument instead of trying to figure out how to make symbols and abbreviations. In fact, keeping the diagrammatic approach at bay was one of our goals while writing the GMAT Critical Reasoning Grail.

This is not to say that the diagrammatic method is bad. It is useful in some cases but you certainly don't want to become that dependent on it that the moment you see a critical reasoning question, instead of trying to understand the meaning of the argument you straightway start putting your pen to paper.

Note taking in CR works the same way as it does in RC. If you are taking some notes in RC then you may want to consider doing the same of 30-40% of CR problems you face on GMAT. The reason is simple you are going to be under stress during verbal section and working memory decreases under stress.You dont have to do a big T diagram by MGMAT.Rather some abbreviated notes about what you are reading to keep your focus on CR problems.Refer to any of the Stacey Koprince article on CR problems. She has a nice abbreviation system.