If you have a difficult time drawing/painting trees you should break down and study, in sketches, your understanding of the form(s). Remember that creating reality on a two dimensional surface is really creating an illusion. If you think this way: 1. where is the light coming from, 2. what are the patterns of dark and light I am seeing, 3. where is my eye level, which implies space, 4. what is placed where in the space, where is the background, mid-ground and foreground, 5. what is over lapping what. These ideas happen not necessarily in this order. The space of a landscape needs to be organized in a manner that makes visual sense. The principle of thirds can help.
If you work from life or a photo it is your decision where to put your ideas on the canvas. The trees are sometimes separate, like a portrait but often trees are in groups. Look to organize the groups of trees that make a good design. Don’t put them on the same level in space, nor evenly group them.
Remember that what ever idea you come up with, don’t be literal. Come up with a plan and then re-evaluate thru out the entire painting. Come up with structures and patterns and then let them integrate and not be separate hard edge forms.
Below is some processing I am doing for a painting of Maine with the trees, rock and coast line. I am looking and researching information. Once into the painting, the ideas break apart and new ones arrive. Keep a fresh eye and keep the search going thru the whole painting. Don’t take any of it for granted. You don’t want symbols, you want observation and fresh information.
The painting is not finished yet but I have a dynamic start.
Below are thumb nails of other trees and a class project.