I know this has been stressed before but repetition is essential. If you go through a bunch of CRs and analyze the stimulii it becomes easier to spot the conclusion, supporting evidence, and come up with the underlying assumption. This saves a ton of time when evaluating answer choices. The same goes for SC, if you have a checklist that allows you to quickly evaluate sentences you can narrow down your focus, and discard wrong answer choices more quickly. The MGMAT SC
book really does a good job of outlining the process.