Requesting Map Assistance

[spydersman]

Greeting fellow cartographers.

I'm trying to make a regional map for an upcoming D&D campaign. This is my first foray into map-making. I've been using some tutorials on this site, which have been super helpful. i still seem to be having a few problems. For reference, I'm using Gimp 2.6.

1. my forests don't look foresty. the edges are ok, but the middles look more like plateaus.
2. the borders of my mountains don't seem to blend nicely with the grass/dirt layer. i like how vivid they look, just wish the base would not stand out as much.
3. despite using the exact same colors, the mountains areas on the little islands don't look right to me, I've tried a few other color combinations to no avail.

aside from those three major things I'm pretty happy with the way it looks.

I will be attempting to add a whiteish area up north for snow, and a dark swampy area in the south. Any tips on how to do that without changing anything else on the map?

I couldn't attach the Gimp file as it was way too large (about 19mb) so i attached a jpg instead. If someone was willing to assist I'd be more than happy to send them the Gimp file over e-mail.

Thanks in advance for any suggestions/help, etc