Actually I think I would look for their bedding area's & feeding areas. Then I would either setup up before or after the rub line depending on how the deer are moving. If you ffound a ton of rubs in one area & it is thick cover you may actually be in or near a beedding area. I think rub lines really help show how deer may be moving & if you have some nice bucks in the area. With that said let them guide you to a great stand sight, just don't always feel like you have to sit in the rubs.Rubs are a great tool for showing a bucks travel lanes, now if all those rubs are in a great funnel (grown up fenceline running between fields) then you would want to setup in the rub line or at the beginning or end of the funnel & hunt when the wind is right!

Good Luck!