Thanks guys and galls, your help is really appreciated! I must say I hadn't expected this to be such a steep learning curve, but I'm happy I've at least made it through the foothills by now. Learning curve peak, here I come! Well, sometime in the next million years anyway .
Below you'll find my next update. The most visible change is the parchment texture of course. It's a blend of several parchment textures I've created over the years - I hope you'll like it. I also added a few more mountains to the central ridge in order to break up the linearity a bit more (I don't think the issue is as strong there as it was in the western mountains), and I think I can reduce the size of some of those mountains by just nipping off a pair of foothills here and there. That's me being lazy, I know, but I really don't have the courage to begin drawing them from scratch again .
Another addition I did was a hill ridge linking both mountainous regions (and providing a nice border region between the lands north and south of that ridge, but that's for later). And last but not least, I reintroduced a first handful of rivers. I'm still not sure PS's "find edge" filter is the real deal, it's funny the effect can't be tweaked as in GIMP. I'll leave the river edge for now, but I might decide to do them by hand in the future. If I manage to muster up the courage.
Okay, enough blah blah blah. Here's the update:
### latest WIP ###
(what's the deal with that "latest WIP" tag anyway? I copied it from somewhere and I kinda like it, but I have no idea why people actually do it?)