Hi feathersandcoins!
I adore the expression in this drawing, you did good on it!
If you don't mind me asking, did you base this style on cartoons or did you go for a more realism effect?
The idea behind drawing more detailed cartoon styles is usually that you have some grasp of basic realistic anatomy that you can then reform into something less realistic (ergo cartoons). I made the mistake of jumping straight into Japanese animation style, rather than learning how a real face looks from the start, and it made my progress more difficult later on. Like Akiresa said, focusing on anatomy is important, but more important is to focus on realistic anatomy. If you refer to the gesture studies in our tools, they are great at helping you understand how a real face, body and hands are constructed and look in different positions and angles.
A very important lesson: "Draw what you see, not what you think you see." We often draw things the way we think we see them, rather than how they really are. That's why it can be really difficult to draw things properly. A popular trick I've seen tells you to take a reference image (like the image of a horse), then flip it upside down. Now draw the upside down horse! You're forced to draw the lines as you see them, because you don't know how to draw an upside down horse. Maybe that can help you?
Either way, I think you did a great job at the image, and I hope you'll have fun practicing more!