i actually did start with lineart. i then made some colored layers and deleted the layer with the line art, so as to make the picture look realistic. after all, not everything has a black outline. thx furyofroy, although i was hoping more for info on doing bark/leaves (so tough for me, considering you don't actually paint every individual leaf). XD

The white stuff in the water doesn't really go with it... And uhh using the blur tool is a cheap way of doing it but.. IDK. The tree's roots look like they need to be elongated or whatever because the one kind of bluntly goes into the rock then stops... Uhh and the clouds just look like streaks. =P Sorry I still think this looks cool if you don't study it a whole lot! ^^;;;

Ok, so I just watched your animation to get a better idea how you went about doing this. Besides the fact I think you completely overuse the smudge tool, you used it well. I personally think smudge works best with liquid substances (water, fire, clouds, etc). And in this case I'll have to disagree with kazukie, I think the water looks fine.
One general problem with this piece is while you have good local shading, you need to focus on the overall shading of the piece, from end to end. In order to give your piece more perspective, you should consider the gradual lighting from back to front, in addition to local shading.
In the case of the tree, I think you have the general idea down, and the leaves don't look terrible. Perhaps more concentration on the structure of the tree. For example, how big do you imagine the entire tree? What type of tree are you trying to draw? The shape of the base and branches will be governed by the answers to these questions.
For shading the tree, for one, I would not use smudge on the bark, it totally ruined the beginning of what could have been good shading in your animation. Again, of course, it depends on the type of tree, birch for example has quite different bark than most trees. But for a stereotypical tree (lol), I would use a combination of diffused brush, vertical strokes of good contrast, and then an overall shading from edge to edge over that.
For leaves, well, what you have isn't terrible, perhaps a little more differentiation...
Anyway, it's not really a bad piece, and the animation didn't corrupt so you could edit it further. :-)

ooh! thanks guys :) i will try to edit this (i usually don't even bother trying since it screws up 90% of the time). i might just redo the tree completely, and definitely fix up the shading. when i was shading, i tried to darken the front and lighten the back more, but that lost somewhere along the way :(