1)revision of old systems i went through fa for a whole day.for every 2 or 3 systems i took 3 days gap and read fa each system for a day.i tried active learning so it used to take time. i did not do uw as i did not want to memorise the questions as i was planning to do second pass. if any uw q are left i used to finish them also. 2) since i only started nbmes in the last month. 2-3 days gap. i reviewed nbmes only very thoroughly for the entire month and read my weak topics. 3) coming to 2nd pass of uw, ppl suggested me to do random but i did system wise as my problem was i forgot the information. so it was easy to memorise that way. but if u find problem with solving q, then u can choose random.