Here is a way to organize the complex information of an interior forest. This will work no matter what your rendering style happens to be. Whether you are an impressionist painter like me or a realist, the basic building blocks for the picture are the same the only difference is how far you want to carry the finish.
The challenge is to arrange the information to give you the illusion of space where no horizon is apparent. Forest scenes work best when you use clearings to establish a foreground, middle ground or background to help divide space in the scene. It doesn’t matter if you are painting jungle or alpine forests, the lush foliage of summer or the bare branches of winter trees; the abstract qualities of design still apply.