Little_John -- you might want to try a more "impressionistic" approach. Until you find a competent teacher, I'm here to share my ideas :-)
What I see is you making great sweeping swathes of color (which is great, if that's what you're after). Believe me, I find it way too tempting too. Here's a demo of a technique to try to help you break it, which should help in general.
The idea is to think like an impressionist, and try to get tiny blocks of color, but each one correct for where it is. Here I'm working with a small paint roller to force myself not to think "brush-strokes". You're trying to break the "pencil" habit, perhaps the brush would be better for you.
So here are three steps towards doing your waterfall picture... I couldn't NOT do the big stroke to begin with, just to give myself SOME structure to work from. Then, as you can probably tell, I'm just working around the picture, trying (as I said above) to get just the right blob of color, JUST for where I'm putting it. And I'm doing the watercolor-like thing of just using the blank page for white. OH YEAH: I did these at 768x1024, then made them smaller to keep them reasonable from the forum's point of view.
And, of course, these aren't finished in any way... once you've got this kind of structure, you can go in with finer detail, different tools, etc. But it's a place to start from. And I think it's easier to get more "natural" colors this way, rather than working from big slabs of specific colors.
And that's it... let me know what you think.
WARNING: ArtRage can cause serious loss of time, and excessive smiling! Use with care! Frequently!
“All creativity is an extended form of a joke.” – Alan Kay