the cropping is sharp in some places and softer in others, i personaly feel that softer looks better.
the wings dont really work with anatomy and perspective, its left wing is placed wrong, jutting out almost side on, while it fits with the other wing it doesnt fit with the dragon itself. did you piece the wings together then place it on the dragon? becuase thats the impression i get.
the shadow would also show on the side nearest us.
i can see a bump for the arm but thats it, it looks wrong in my opinion, try changing where the arm would be so we can see it clearer
the overall shading of the piece is rather flat, while smaller sections are shaded showing soem form the overall shape doesnt have changing shades which is realistic and gives he image a flat feel to it, add more dynamic shading and dont be afraid of contrast.
its a nice piece, but like most theres room for improvement, just keep working at it =)
PJB21