Smart practice makes perfect and not just practice alone. It is very imp to relax and do other things while studying for GMAT. Do not get cooped up in GMAT mindset all the way to the test. Make sure u don't forget to relax, watch movies, go out etc.
First think abt ur weaknesses and create a 4 week schedule for yourself and break down each day on what u wud like to accomplish that day. Keep it simple and stay away from gulping it from tons of resources. During last 2 weeks make sure you do 20 questions (new questions) of all types each day, so that u get in the groove of the real test and practice every ques type.
Stay focused on OG for last few weeks, nothing comes closer to the real test than OG. Stay calm and keep ur mind fresh by engaging in other stuff than just GMAT.
Good luck !
You mentioned that during the last two weeks, make sure to do 20 questions on each type of questions, where do you find those questions? I think by then, I probably have completed most of the questions from the OG Guide (I've been studying since June)...Do you know where to find new material and also where to find questions that would differentiate each of the question types?
What would you considered as "smart practice?"