Zshpere first rough skitch first.
then re-topology.
then paint a displacemap to bump major detail on the new smooth hi res mesh.
then paint texture and fine details.
then generate normal and diffuse map.
and it is the output.

I am quite satiflied with the result myself, so I would say it is Finalized.

2416 tris Mesh + 4kx4k Normal + 4kx4k Diffuse

Because of filesize, I posted a few loseless source, hi res zbrush shots and wire shots etc, somewhere else
which could show how I made it.
The Link is here: http://www.ec2up.com/a.php?a=vgcllwnono

Please tell me your comments, thanks