Tree Studies

I need to understand trees better.  So I did a couple quick sketches.  I learned that trees are a funky balance between random and flowing, sporadic and elegant.  They have a general flowing gesture, but use really random paths to get there, with the often random change of course of the flowing gesture.  If you make your trees too flowing, they become more stylized "feeling" of a tree.  if you go completely random, it looks like lightening, or scribbles.  Trees are balance.

I found the aspen tress rather simple and easy to capture the gestures.  But after all, black and white trees look pretty good in black and white.  But the other tree was a bit more of a challenge.  The texture is so intense when you get down and analyze it.  The only way to approach it is to create strokes the mimic the texture.  (I wonder if there are tree bark brushes for photoshop?)  Same with the leaves.  No way you can draw each and every one of them.  So I am a bit fascinated with techniques to draw trees and make them look good.  Any tips or ideas would be appreciated.