Freodin: maybe a little tea-staining via watercolor brush, of just the coastal areas?

RakeWorm: No: Embarassment = verboten. Also no frownie called for. It's a good start - enough to entice several of us to encourage you to make it better ! If t'were embarassingly inept, it would just be ignored. You'll get it; "just keep swimming, just keep swimming..."

I bet you could get rational river networks out of this by just selectively erasing a few segments.