I have a hard time wrapping my head around the way canine faces work, the size of the muzzle & the flexibility of the mouth always throws me off. So I did some studies to practice.

When studying/heavily referencing a photo I trace it first, breaking it down into the underlying 3d shapes (red). Then I re-draw those shapes by hand (blue), and use that as the basis for the final piece. I reference those shapes to add lines/details to suggest depth, or for shading (which I only did once since I spent way too long on it and shading wasn't really the point of this anyway).

The idea isn't to perfectly re-create the reference, just to understand it well enough to make a more believable result. I'm fairly happy with these overall, I definitely learned something from it, but I think I need to do more with a focus on finding larger shapes first - I started too small/detailed here & struggled with proportions and perspective as a result. In the long run I'd like to study human & animal faces enough to combine traits from both for a more anthro look.