I'm trying to aim for king of an exo skeleton kind of head. I've just ran into a bit of trouble with the eye and the skin shading.
Any suggestions as to what methods I should take in improving this texture.
Thanks Mc.

Nice head, the shading is great. But i think you should tone it down a bit. I think you should give it Fangs on either side and not so piled. I'm not sure on the back of the head though, I think you could show some of the brain, or Under the The skull, Eg; Raw flesh, blood etc.. you would have to map the back a bit bigger and In a different shape to make it look realistic.The eye should Have some kind of of Bone or pocket to hold the eye or something to make the eye have more definition. You can do this by doing some heavy shading, this will make the Eye look less bright- About the eye, Give it Vain's, and make sure you have a coloured ring surrounding the pupil, if you don't want to do that, its fine but I think it would help.
And the final thing I have to say is that you should do the mouth covering the teeth for this head otherwise it looks cluttered. But I like it nice start.