Quote Originally Posted by Rob Oplawar View Post
How do you even do that? I need to get my ass back to the tutorials.
Like the little oddly shaped seam in the image above, for example. I mean, I can conceive of ways of doing that, but they're all intensive on the manual editing and would produce something that wouldn't subdivide well, and I'm pretty sure you're doing some sort of subdiv modeling there... Anyway, neato gun you got going there.
It's a separate object sitting slightly above the surface. Just copy the surface you want to add detail to, subdivide the copy as needed, delete the excess faces, retopologize as needed, extrude it off the original surface and then extrude it back to give the illusion of an indentation.

Nice work, neuro.