Part of the art of 'treescapes' is imposing some order on the essentially chaotic, fractal nature of vegetation: the human eye tends to look for patterns and order, so some element of that is usually necessary for a harmonious composition (if that's what you are after, rather than documentary).
So, all these images are, like the curate's egg, good in parts: but I feel that none of them is totally successful for various reasons. For example, the twisted vine in #4 makes a nice focal point - but the blurred foreground branch is obtrusive and spoils the effect. #1 has a nice repetition and contrast of bark textures, but simplifying it further by having a background that doesn't draw attention would be even better.
A good start - and the more you practise, the more you will get your eye in and see everything in the frame - not just what you are interested in; we have to train our brains to see what the camera will record.