GMAT preparation kick-off

I took my first mock GMAT in CAT format today. Got a score of 660 with pathetic performance in verbal. The complete score report looked like this:

Section	Scaled score	Percentile
Quantitative aptitude	50	97
Verbal	29	87
Total	660	87

The analysis is as follows:

Section	Type of questions	Incorrect	Comments
Verbal	SC	9	Idiom problems!
	CR	1	Silly mistake
	RC	1	Silly mistake
Quantitative	PS	3	2-silly mistakes
	DS	2	1-silly mistake

The sentence correction mistakes screwed my whole score. I need to really work on it. I can't figure out all the god-forsaken idioms! Most of the questions seemed to be idiom-based.

Furthermore, I need to completely eliminate the silly mistakes. On a couple of questions, I got the correct answer but marked the wrong one. This appears to happen more often than not on the data sufficiency questions.

Equally important, I need to learn the essay templates I wrote for myself. In the middle of it, I realized I did not remember them. Anyway I still wrote the essays. Let's see if I can convince someone to review them for me. :)

Here's hoping I can do this better after putting in some more effort!