X-Men Origins: Wolverine

Wolverine drawing process, one drawing lesson i learnt from this artwork would be this,when I started the artwork i thought that it will be easy to draw as of now I have made more heads than ever is a single month so I am should be in a flow State some thing but I was very wrong with that Idea as when I made the rough line art and then proper line art or final line art I saw that the sketch or drawing is bit off but I couldn't find what is it without checking the actual problem I went to shading