I've been working through, as well as trying to figure out how to communicate, seeding a region with a hub community (ala a settlement) and then determining how that community spreads out from there: where it can spread to, how far it can spread, etc.

The idea is that a community that hits certain strength thresholds (which I call magnitudes), can spread through favorable terrain up to a certain radius away and also, as needed, form sub-communities of smaller strengths. If a sub-community is placed on very favorable terrain, such as a river or coast, it can increase one rank. Spreading can then occur from those communities as well.

I started out with one settlement (at 018.012) and then used the process outlined above to walk through that community spreading out from that single hub to form new connected sub-communities. Here's the final map, with some sites added in (the star icons) towards the end for a couple of thought experiments:

The roads came about naturally to connect the sub-communities to each other and then back to the hub. I'm still fiddling with the procedures but so far so good from where I'm sitting!