Links to Final Proposal References:
https://www.artstation.com/artwork/GyokN
https://www.artstation.com/artwork/XB1drY
http://www.zbrushcentral.com/showthread.php?195454-quot-Is-this-some-kind-of-bust-quot-my-zbrushworks/page11&p=1216106#post1216106
http://www.zbrushcentral.com/showthread.php?195454-quot-Is-this-some-kind-of-bust-quot-my-zbrush-works&p=1150220&infinite=1#post1150220
https://www.artstation.com/artwork/wOGK9
https://abduzeedo.com/splendid-digital-sculptures-james-w-cain
http://www.zbrushcentral.com/showthread.php?175208-Dishonored-The-Character-Art-(new-images-pg-3-5-6)/page5
https://www.deviantart.com/corderostorm/art/Dishonored-Assassin-Daud-fan-art-625870298
http://www.zbrushcentral.com/showthread.php?175208-Dishonored-The-Character-Art-(new-images-pg-3-5-6)
https://www.artstation.com/artwork/L0VDK
https://www.artstation.com/artwork/gW4ZE
https://www.artstation.com/artwork/0Zx5w
Some tutorials: