Hi Dominic, welcome to the Guild. First off, you have picked a difficult style to work with: namely, a hand drawn (painted) style. It usually takes time learn the techniques to pull off this style well. It looks like you are just stating off on the path of learning this style and could use some pointers on technique. There aren't many tutorials here on painting, but there are some on drawing/painting maps by hand. Here are some you may want to refer to:



There may be more, but these are the ones I'm aware of. At any rate, I think they will offer you some pointers on ways to improve your map.

As to my own comments, I can't tell what kind of brush you are using, but between the brush strokes and the smudge tool, the geographical details of the map all look blurry and out of focus. Nothing really looks well defined in the map. You may want to try using smaller, cleaner brush-strokes to distinguish, say, the land from the sea. Anyway, hope the tutorials are useful.

Cheers,
-Arsheesh