I like it xD I love how in the shadow the hand is holding the cigarette, like it's a shadow of reality, in the past. It's very good at representing your idea of 'quitting smoking'. The sketching of the hand is very good, though I think there should be a more play on the shading on the hand as well to create more form, though it is very good in itself. Also when shading from the darkest point of the shadows, to the lightest, you can try to blend the shadows more, from darkest to lightest, to create a smooth variation in shade. I hope I made that clear, I'm not good at explaining xD. Overall it is very good, it really makes me think.