After a tree loses its foliage in the late fall and winter, we see the bare branches and trunk of the tree. To paint a tree in this state, you really only need one colour (brown) and a round-tipped paintbrush. This is in many ways an easier activity than painting a tree in full foliage, which can more easily look cartoonish or simple, and thus unrealistic. Still, you may wish to study pictures of trees without their leaves before proceeding with a painting of a winter tree, so that you can make informed decisions as you paint.
Dip your medium-size round paintbrush in a dark brown colour--preferably, a cool brown rather than a warm brown.
Place the round paintbrush on the canvas at the base of the location where you would like to paint the tree. Paint the trunk upwards in a long, relatively straight stroke. At the top of the trunk, paint a V-shape to represent the split of the trunk into two thick branches. Paint the two thick branches approximately half as thick as the trunk. Paint the branches upward and outward. Make them approximately 1/3 as long as the trunk.
Paint a V-shape that moves upward and outward at the end of each of the two thick main branches, approximately half as thick as the main branches, and about 1/2 as long.
Paint a long stick shape that moves upward and outward at the end of each of the branches you painted in step 3. These branches should be about as long as the branches you painted in step 3.
Paint a V-shape at the end of each branch you drew in step 4. Now begin to paint smaller and smaller branches, moving upward toward the sky, occasionally branching out in V-shapes until they end with thin, fine branches.
Paint highlights on the tree. Dip your paintbrush in the white paint and mix it with the brown. Then, apply the paintbrush to the canvas. Paint a line of lighter brown on the trunk and major branches, on the side nearest the sun to make it look as if the light is shining on your tree.
Paint shadows on the tree. Dip your paintbrush in black paint and mix it with the brown. Then, apply the paintbrush to the canvas. Paint a line of darker brown on the trunk and branches, on the side farthest from the sun.
You may decide to add some heaps of snow onto the branches for a little more realism. This is easy to do in oil or acrylic paint because white paint can easily be painted over the branches of the trees. However, this type of manoeuvre requires some planning when working with watercolour since the colour white can really only be produced through the absence of paint on the paper.