ibbys,
The
MGMAT guide is a wholesome guide that is essential in your preparation for your GMAT.
Your method is somewhat acceptable but it would be better if you could tweak it so that better results can be obtained.
Start off with the Manhattan SC Guide Basic chapters( As you said) and then instead of opening the OG12,open the OG10 and work on the SC questions. This way you will gain familiarity of the concepts of the questions without having to sacrifice the OG12 questions. Then, once you gain a certain level of confidence, you can start with the advanced chapters and complete OG10. Remember, this does not mark the end of your preparation of SENTENCE CORRECTION. You have to move on with OG12 which has the latest collection of SC Questions. Then, during your second reading of
MGMAT SC Guide, i recommend you do it as the Guide is designed as it has been designed that way for a reason. Why reinvent the wheel ? Read each chapter and solve the questions at the end of the chapter. Continue till the end . Your second pass would ensure greater ability and confidence with Sentence corrections.
I would love to hear your comments..
PS: The best method would be to first solve as per the guide and then move on to OG10 . Since you wanted to start with
OG, I recommended you to try this method.