Building up the pilot’s helmet
I mask off the shape of the helmet, then go to PolyGroups, click Group Masked and reverse the mask. In the SubTool menu, I click Extract and Accept. I can now go the Deformation menu and adjust Smooth by Poly groups. This will give a clean edge to rim of the helmet and creates a SubTool in my SubTool menu. I now move the ears out to create a nice ear/helmet silhouette.