By "put here" do you just mean this?
I think it's pretty obvious that's not what he meant.... and that he's the creator of both these pieces.
Anyway, welcome to the forums, Jasper! First of all, I want to commend you for picking a light source in your images as opposed to "pillow shading" as many beginners are prone to do. Well done! However, both faces still seem very flat (especially the first) because each shade is relegated to a broad solid area. There's a dark skin tone you're barely using in the first piece that would add a great deal of depth if applied to the darkest areas of shadow. Remember you can sculpt using volumes as well! Also, it's true what Singularity said about the importance of photographic references. Even if you don't have a picture of yourself handy, any reference photograph of a human face would provide a wealth of information about human anatomy.
