Enhancing a scribble

[Elrondsen]

Hello,
this is my first thread here, presenting a hand-drawn map by myself.
To be sincere it's more a scribble than a map, since I made it with only blue and black pens and a dark green marker in about an hour.
So I decided to enhance it in Gimp - in fact it's my first exp with it.
The continent is called Harvint.
Critics and advice appreciated.

Here are rough scan and WIP with coloured forests.

Now I'm working on the coastline. I know - I should've started with it.