For designing models for human characters, I usually use a tool like a wrap deformer to ensure the shape fits the head for example.
In the image, I made this by tracing onto a head scan (had to convert it to NURBS through Rhino) and patching each section. Now I would like I see a way to not only deform the shell onto the head, but to relax it to remove any weird bumps (think relaxing a mesh in blender while keep its overall shape).
I did see a wrap option in Plasticity but I don't think it works