LOL, yes, I do a 3 pass shave on my whole head. It's time consuming but well worth it. The back is done entirely by feel- but I've been shaving my head for over 12 years, so I've got a lot of practice in. The DE shaves are better by far than cartridge shaves on the head, which is why even after my recent mishap and extra hair growth, I still couldn't countenance going back to the Schick Quattro, even once.
Tell me about corking- what is the procedure?
Corking involves running the edge of a new blade into a cork 2 or 3 times on each side. It apparently helps to smooth out imperfections or remove microscopic metal bits that can irritate the skin during the first shave with a new blade.
Full details and pictures here: http://badgerandblade.com/vb/showthread.php?t=61894