Below is a step-by-step drawing tutorial.
Draw two ellipses like the one shown.
We can now sketch the Owl. As a guide, use the ellipses to add the details. The elliptical guide will be removed at a later stage.
You can add more borders but make sure they are not too bright.
Once we have an understanding of the shape of the Owl, it is time to start shading. You can begin shading each area by erasing the guides as you go. You don’t need to delete all guides at once. Only the ones you are working in will be affected. The guides around the Owl’s body will help you see its shape. Smoothen your shading with paper towels or tips.
We can now add details to the feathers. To create separate feathers, draw an oval around the shaded areas. Refer to reference images before you start drawing a down jacket.
To fill in the gaps between the wings, we now add smaller feathers. The white space allows me to shade the small ovals with their pointed ends in rows. It almost looks like scales.
To add more contrast, add darker details. This makes feathers look more 3D. If you’re drawing from a reference photo, make sure you carefully mark the shadows so your drawing looks natural.
Continue adding details. You should not make the fur look too fine. To make the fur look more real, add some scuffs or plumage to the feathers. But don’t pressure too hard. You could end up making an irreparable error.
Owls have thick fur around their legs and front. For fur drawing tips, see my tutorial “How to Draw a Realistic Tiger”