This is a great example of a hand drawn map... but exactly because of that you should be very careful with the digital effects. The drop shadow on the mountains and forest details rather destroys the feel. Try to do without that.
If you think that bare triangles are too simple to represent your mountains, try to add some lines for shading.
For consistency's sake you could also try to redo the coast line with a soft brush, similar to the rest of the linework.
And finally, turn down the intensity of the labels a bit, or add some slight structure. Pure white looks rather fake in these maps.
But all in all... for your claim that you are not an artist you managed to deliver a rather nice piece of art.