DETAILING THE HEAD
Start sculpting with a low level of subdivision and add complexity only when forms are correct.
Make sure you create and place the eyes early on, as a separate subtool, otherwise you are going to end up remaking the eye sockets, or worse, most of the structure later.
A fast method for detailing is grabbing a face scan from
texturing.xyz and adding it to the sculpt using layers. In order to be able to match the scan to the head, retopo and UV it, and use the Photoshop workflow extensively explained on the website. A faster alternative is using the ‘Killer Workflow’ with Zwrap.