This is too cool; I'm only sorry we didn't pick up on it earlier! Clive Barker, always willing to give his massive fanbase an inside look at his creative process, has been updating his Facebook page with sketches and some early design work for HELLRAISER.
Look below to see a few sketches of Pinhead (complete with notes) and the Cenobites, which are dated 1986. I think I've managed to read Barker's handwriting on the Pinhead sketch. Seems to read: "Pinhead is making the death machine work. His pins (some of them) give off lightning, which dance between the killing cogs! They should be silver blue."
The rest, I must admit, is unintelligible to me, but what really matters is the enjoyment obtained by looking at the artist's rough drafts. Hopefully you dig them as much as we do.
To see more, check out Clive's official Facebook page.