Shade the pupils solid dark, while lightly shading the iris. Draw additional tiny strokes around the eyes to enhance the feathers around it. Continue this motion for the entire body. Erase the guiding lines. Add some details to the tree branch.
Have fun with the eyes, if you want—you can make a serious owl, with in the middle straight ahead; an owl looking at something, by drawing the pupils pointed left or right; or a goofy, cross-eyed owl.
Omit or add more details to the drawing as you go, for example a tree branch the owl is standing on. Experiment with backgrounds using a different layer.
Add optional lines for details to the tree branch or other background.