Thank you guys for the feedback! I'm notoriously starting new maps, leaving older projects unfinished. While i am somewhat happy with my mountains, i usually stuck doing the forests and then losing interest :/ So instead of opening a wip-thread for every single one of them, here are some unfinished maps i started the last months:
The "Grant&Karst" map i posted above is a typical case, i finished the mountain linework and some blobs where the forest should be, then started trying some things with the forests and skipped them in favour of labels and stuff...
Grant_Karst_WIP_III.jpg

On this map, something similar happend. With the forests ahead, i switched to making the border and some nice ornaments and never came back...
TheDawningJarldoms.jpg

Here i planned doing a more "plain" map (with political borders), but it looked a bit too empty in the end. After some attempts of doing mountains and forests, i decided it isn't looking that bad without this stuff...
FernhagPlain.jpgFernhagPolitical.jpg

Finally a piece, where i tried to make a "proper" isometric coastline (in fact i just compressed it vertically to 57,7% as suggested by torstan and xpian) as the mountains i go with at the moment look somewhat off on the above maps. Haven't finished the mountains yet, but i somehow fear the forests ... maybe it'll be an arid, rocky island
UnnamedYet.jpg

Maybe it's because i somewhat tunneled on iso maps since i like the mountains i developed in my Tarkir map (also unfinished btw.). I just haven't found a way to draw forests that fit the style of the mountains somewhat and are not to detail-heavy. The forests i started on the "Grant&Karst" map are not too bad, but they took way too long to do.
While these maps are rotting on my hard drive, i'm working on two encounter maps for an rpg session, and the best thing is: there are no forests on it!

Cheers,
AL