Hi there. Hmm well for starters I think its just simply too plain, or simple. I think you can put your tones to better work and use the white for highlight, grey for midtone and black for shadow, and actually shade the piece. That's just personally what I would do. And also white-grey-black...very bland. Spice it up with some colour, maybe like pink-yellow-green, or yellow-green-purple...just something more interesting in general.
