Step 20: For a cleaner look, erase as much as you can of the initial guide lines. Don't worry about erasing all of the guides. It's okay to leave some behind. Re-draw any final sketch lines you may have accidentally erased.
Final Step: Add some shading to your fox drawing to give it more dimension and volume. Pick the direction of the light source when shading so that the shadows are consistent with it. Vary the pressure on your pencil to get different degrees of tonal value. Don't worry about shading too smoothly. The rough value gives the coat a furry texture.
Add a cast shadow underneath. This helps ground the fox so it doesn't appear to be floating.
You can add even more value throughout your fox drawing for extra detail. Use a dark value on the tips of the ears, the nose and the side of the muzzle. Use a medium value for the top half of the head. Leave the bottom half (the cheeks) blank.
Separate each individual stroke a bit so that the white of the paper comes through and creates a fur-like texture. Cover the top half of the head in value, then continue to add a medium value to the body as well. As you shade the body, use strokes that go in the general direction of the fur. Foxes have dark brown or lack legs and feet, so use a dark value for them too.
Shading can be time-consuming, so be patient and take breaks. Use a medium value for the fox's tail. It's always a good idea to use reference as you draw. If you'd like, you can add more value to the chest. Don't forget to pause the video after each step to draw at your own pace.