Trees confound me. They clutter up the background fiercely, and completely flummox the camera when it tries to deal with the extremes of light, from the pure white sun to the blackest shadows of the leaves. It's a recipe for disaster that I've never yet managed to sort out.
Consider the following image. In order to make the subject stand out, I had to darken the background significantly. Still, the busy background competes for the viewer's attention.
The next one wasn't much better. Despite my great idea of having the subject repeated throughout the image, the overall effect is essentially ruined by the trees cluttering the background.
My plan for the time being is to simply avoid trees.