Any communication will initially have to be, well, standoffish.
There are a lot of options:
Radio contact is easy, but they'd have to have a radio. It's pretty straight forward to establish communication and talk about things from a mile away.
Another option is dead dropped notes and letters, but that requires infiltration of overlapping spheres of control. Historically this would be sent with gifts or tribute. If you suspected someone of hiding in the woods nearby your location you might place an easily seen beacon with a note or sign indicating your intentions and explaining to anyone that finds it how to proceed with the contact ("use this radio channel", "go to this place", "we are looking at you now, put down any weapons and lay down or you will be shot") and you may even leave some food or a blanket to show that you mean no harm but early on this may be used against you so it's not recommended.
I feel like a lot of old time polite traditions would come back quickly. People used to always trade something every time they met someone, or sometimes it was customary to bring gifts to show that you brought value to your new acquaintances.
There are a lot of options:
Radio contact is easy, but they'd have to have a radio. It's pretty straight forward to establish communication and talk about things from a mile away.
Another option is dead dropped notes and letters, but that requires infiltration of overlapping spheres of control. Historically this would be sent with gifts or tribute. If you suspected someone of hiding in the woods nearby your location you might place an easily seen beacon with a note or sign indicating your intentions and explaining to anyone that finds it how to proceed with the contact ("use this radio channel", "go to this place", "we are looking at you now, put down any weapons and lay down or you will be shot") and you may even leave some food or a blanket to show that you mean no harm but early on this may be used against you so it's not recommended.
I feel like a lot of old time polite traditions would come back quickly. People used to always trade something every time they met someone, or sometimes it was customary to bring gifts to show that you brought value to your new acquaintances.
I dunno whether to feel shamed or honored ... 
Guess it would depend on who I was talking to, huh? 
Or then again ... I might just go "full auto" on them ... 
