Step 15: Use the angled line on the top, left side of the bulldog's head as a guide to draw the other ear the same way. Darken the angled line but make the shape curvier. Add a few short strokes and lines for the fur and structure.
Step 16: Use the big circle as a guide to draw the rest of the head. Darken the top edge but make it a bit flatter. Follow the path of the initial circle but make the left side wavier for the structure around the eye. The line for the head below the eye should be narrower than the original circle. Draw a few curved lines to the right of the jowls for a bit of structure on the bulldog's jaw. Draw more curved lines along the lower edge of the initial circle for the loose skin on the dog's neck.
Step 17: Draw a series of short strokes and curved lines within the shape for more detail on the head. Using a series of short strokes, draw a curved line over each eye for the dog's brows. Add a few more short strokes below the eye on the right for the bone structure. Add longer curved lines above the eyes for the loose skin on the head. These curved lines also give the bulldog more expression and character.
Step 18: 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: Using a medium value, add some shadows to give the bulldog's head more dimension and volume. Use a darker value in certain areas like inside the ears for deeper shadows. Shade the nose but leave a strip blank near the top for highlight. Vary the pressure on your pencil to get different degrees of tonal value. Shade the inside of the bulldog's eyes using a medium value but don't overlap the tiny highlight circles. For a more detailed guide on how to shade, check out this tutorial: How to shade.
You can stop here for a white bulldog or continue to add value to give the coat a pattern. For this pattern, create an irregular shape under the nose and around the eye and shade it in. Add smaller spots on the muzzle too. It's a good idea to use reference as you draw for a more accurate depiction of a bulldog. If you have a pet bulldog or a similar dog breed, try to duplicate its fur on your drawing. Add a bit of light value to emphasize the white fur. Shading can be time-consuming, so be patient and take breaks. Don't forget to pause the video to draw at your own pace.