GReat model.. You got a good mesh to work with and getting a good face mesh is half the battle i feel.. and if you really want it to look realistic(over done).. you can spend hours pushing and tucking that bad boy.. but let me lend you alittle fine arts history advice... in the classical period every one was doing realism to death and as art progressed stylized pieces became the top winners.. and its so funny how history repeats itselfs ;) so stick with style over realistic cause there's plenty realistic stuff in the world