I want to start playing with the ranges of villains but I dont feel confident estimating.  For an UTG 20% open for example, do I plug in big pairs, A high rundowns, K high rundowns, one gappers, two gappers, all suited all rainbow all 3 to a suit all double suited, some double pair hands say 99xx +... I dont know how I can actually estimate it accurately to gauge my equity in different spots...and Im sure Ill end up miscalculating my equity in every spot.  Anyone who can tell me how they started out doing this Id appreciate it.