I hear you. CR is a bit tough for non natives because it takes time to analyze the argument. I'm not going to overload you with suggestions. Here are the 2 things that worked for me:

1.) "conclusion is the king". The first step is to identify the conclusion and the second is to attack it (and not the premise). When you practice tons of questions, your brain will get accustomed to remove the chaff from the grain (premise from the conclusion). You will take a lot of time initially, to separate out the conclusion & the premise, but its worth practicing. After a few hundred questions, you will not even stop to think what is what and will jump on the options straight away.

2.) Pre-think. It improves your analysis and forces you to create a structure. Lastly, have the courage to use the same process on the exam. Many of us practice one thing and follow a different routine on the exam. Avoid that.
The best part: pre-thinking works for a lot of questions. Strengthening, Weakening, Assumptions, Flaw, Evaluate and even for main idea of RC passages. You may use this to gain some understanding of the concept: http://e-gmat.com/blogs/?p=1750

Having studied for so long, you might have exhausted all the official questions. Don't worry too much. Try to solve them with a new approach and you will find improvement in your score.

good luck!
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My Debrief | Find out what's new at GMAT Club

Don't try to fit things in a formula. This is what I'm talking about. Your approach is so mechanical at the moment (not blaming you), but with time it should change to one based on intuition. That is when you will see a good flow of correct questions in your attempts.

Don't overdo stuff, but practice hard. Try to see why an option is incorrect and finally, don't start with 750+ level questions. Increase your level (and speed) gradually based on your comfort.
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My Debrief | Find out what's new at GMAT Club

I read CR Bible from end to end and am glad that it helped me during my second attempt. I am now taking classes for the GMAT; the teacher uses the concept of assumption that is explained in Manhattan CR. CR Assumption is one of the most difficult sections for me. The CR Bible teaches us that there are two types of assumption question types: Supporter and Defender. The Bible intends to say that the concept: "Premises + (Assumption) = Conclusion" fits only in the Supporter whereas this strategy does not fit in the Defender.

My question to everyone out there is that have you ever tried to simplify this aspect? I am currently fighting with the fact that why CR Bible has come up with two approaches whereas Manhattan has completed the whole book on just ONE concept - P + (A) = C.
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