In case you wondered, I haven't given up on this.

I find myself still searching for a style. I really like the above and I want to finish it some day, but I couldn't for the life of me figure out how to do hills. I also do not find a way of doing a satisfiying background. As you can imagine, fiddling around and not making any progress can get really frustrating. So I tried yet another thing.
It's a bit like a comic-book-style, but I like it so far.

Click image for larger version. 

Name:	Strichcolor.jpg 
Views:	120 
Size:	117.3 KB 
ID:	58911

So while I work on my general feeling for colours and shading to finish the above style, I will occasionally continue to do a map in this style. Just to satisfy my mapping-urges.

I'd still be happy about input on my newest endeavours, though!