First off, what software are you using? Second, what do you want it to look like? Because, right now, I don't see any problem...grab a brush and plop some color down. If you're talking about trying to make your mountains more natural, and less like wasp mud-homes, then you need to use a softer brush in the beginning so that the edges feather out more smoothly. Your post is very vague so it's hard to help you right now; please provide something more specific.