Start with Three Shapes
Mix a puddle of watercolor paint in any color — I chose purple for this demo. Make three shapes on your paper where the tree foliage will go. Vary the sizes and have the edges go in and out — do not make hamburger shapes:)
Rinse your brush and tap on a paper towel to remove some water. Then touch the shapes with the damp brush and pull your brush out to soften some edges. Touch about 1/3 to 1/2 of the most boring edges. Don’t forget to soften some inner edges also.
Calligraphy & Pull Out Tree Trunk
The edges of the trees are the most important areas. Do a little calligraphy around the edges of the shapes you just made. Place dots and squiggles around the hard edges (where you did not soften).
While the foliage is still wet, pull out a twisty tree trunk. This will be the start of the trunk and, if you touch it to the foliage now, it will look like it disappears into the foliage — which is what we want.
Dry, Then Sponge
Let your painting dry. Use a hairdryer if you are impatient. The foliage will dry lighter.
Then use a small piece of natural sponge to apply darker paint. Be careful. You do not want big, wet globs of paint. You might have to dab your sponge on a paper towel first. Test on a practice paper to make sure you are getting small dabs (see left photo).
Finish the Trunk and Ground
Mix your main color with a bit of it’s complement color to make a grey or brown color. I used green with the purple (I could have used yellow). The complement color is the opposite color on the color wheel. Red/green, blue/orange, yellow/purple.
Paint down one side of the tree trunk (I did left). Pull it down and flatten into the ground. Then, with a damp brush, soften the inner side (right side). If your trunk is not dark enough, add more paint to the hard-edged side (left). Paint the other side of the ground and then soften the bottom edge of the ground area with a damp brush.
With a Rigger Brush, Paint the Tree Limbs & Grasses
With a very small brush or a rigger brush, pull up some grasses on the top of the ground area.
Then paint the tree branches. They will be thicker closer to the trunk and then get very thin. Make them twisty. Put a few limbs in the center of the tree in the white area or into the lighter areas of the foliage. Possibly paint one dead branch that twists and does not connect to any foliage.