I think you could totes push your line weight variation a little more. There's nothing wrong with thin line-work, but it gets a little uniform in spots, like the coat, hands and tail.
Also, you're shading with grey. That's fine for showing where your light source is, but that's pretty much it, and there's so much more you can do with shadows. By playing around with the colours of your shadow you can strengthen the mood of a piece, introduce new feelings, and unify colour palettes. You can really use any colour for shadows, so experiment!
einsam
Colbitzer
@ 3:32 PM Apr 17th