Alright, I'm gonna give it a shot at critiquing. First off, let me say that I really like your style~
I'll write about my thoughts for each individual piece.
1. Dang, I really like the way you drew the feathers
But, you've got to be careful of relative head sizes. Either Howl's head is too big, or Sophie's is too small.
2. Haha, it's cute~ Liked how you used the lighting effects here. I don't know much about backgrounds, so I won't say anything about that :'D There are a few inconsistencies in this picture, for example, for the leg that's been raised, you have the bottom of his shorts stopping above his knee. On the other leg, however, the shorts seem to stop below his knee. Also, with his shoe, without a strap at the back, it wouldn't stick to his foot the entire way like that. Kinda like flip flops when we walk in them, they hang at the back.
3. Not much I can pick out with this one, the only thing is that Shang's head looks like it curves upwards and in too much (I hope that wasn't a confusing explanation @_@'')
4. Nothing I can pick out out here, but I'd like to point out that although she's telling him off, Bora doesn't look very annoyed
5. Again, not much, but I feel as if his eyes are just that tiniest bit too close to each other, particularly the one on our right.
6. A few inconsistencies here. It seems like the girl's arms too much too long in comparison to her legs, in fact, they're longer than the guy's arm
Well, I hope this has helped a bit xD''