well..started my prep 3 months before my exam. my first month was when i was totally free so this was when max prep took place. i built up my foundation fr verbal during this one month. quant was never a problem fr me as i was always really good at math.
one tiny tip that helped me and moght help u guys...keep a notepad and jot down any important points tht u are not familiar with in this. go through this notepad thoroughly in the end. for ex. u can jot down new idioms tht u come across durin practise sessions. thos really helped a lot.
and one more thing...be wary of burnout. i made sure i got gmat outta my mind the last 30 days. in the 30 days just prior to the exam, i just did enough so as to keep in touch with everything ie. max an hour everyday and sometimes as less as 10 minutes a day. this strategy worked fr me..doesnt mean it will fr every1 so just do what ur comfortable with...
peace...good luck...
Abhishek sunku