Okay, now I have the list of tribes wrapped up. Should be about 19 so far, which seems a good number. Now they need a lot more of fleshing out, making them into distinct cultures with social orders, customs, and religion. After this is done I can continue to coming up with a more specific geography for them to inhabit. This is a rather upside down approach, but since the setting is all about the cultures and the environments they inhabit, I think this works better than starting with a map and then comming up with ideas what people might live in those places.
As this is a relatively early stage, I am open to suggestions of any kind. Anything that you think might be an interesting aspect or element for a tribe of the ancient lands is welcome. Even if I don't go with a suggestion for a specific tribe, I still might use the idea for another one. So feel free to blurt out anything that comes to mind.