Overall it's all good practice. The only point I would probably mention as feedback is that there seems to be a bit of sketchiness to some of the works. If it's because they are intended to be sketches, I'd say that's normal, however it's worth trying to work on "bigger swings" with your elbow/shoulder to get smoother overall lines, as well as having the undo close to your finger so you can "draw, undo, draw, undo" until you get the perfect line before moving one.
Still, if it's gestures, there's usually not enough ttime for that, but for something like the characters or env studies it should work out.
