Clean Outpost
There are many good ideas about outpost in here i think...
But one thing that would add a load of immersion for my gameplay experiene, is if the outpost get some sort of visuel improvements. I'm not talking about a huge visuel difference, just a small change so it appears like an outpost. It make no sense that an outpost look like a zombie nest with blood on the wall etc... That would be rewarding for me, and make me reconsider which building to claim.