I think that you've hit the most important thing to look for which is to mark runes at resource square intersections to maximize output with fewer runes marked. I also look for the most secluded spots I can find with, obviously, little or no spawn. Typically I would open temp accounts for hardcore resource gathering so I end up placing a 7x7 house somewhere in the middle of nowhere as my resource house (this isn't as easy now that housing on temp accounts has changed). Then I access my main to the house and use it to gather the resources from the house and send them to the bank.