Hand-drawn style region - mountains?

[song]

I'm trying out a hand-drawn style for some regional maps and it started out well but I've been having a fight with the mountains for the last week. They never seem to look 'right' -- I tried making them smaller, larger, tigher, sparser... considered that perhaps I simply couldn't draw mountains and snagged some brushes from here to try... I'm beating my head against a wall.

My latest attempt has, I think, some potential, but I'm not sure it will work going on to do the rest of the map -- there's a large 'knot' of mountains (think Alps) in the lower-ish left where the three rivers start, and I suspect what (sort of) works for a spur might not work for a bulk. Could I get some advice before my forehead develops a permanent lump?

(oh, PS, that river at the center bottom isn't curving around to nowhere, I just cut the region off right at a join, apparently.)