Sometimes the clay just produces it for me. Many of the expressions in my masks emerged when I was intending to do something else. Otherwise, I set up a mirror and use my own face for the information I need to convey a look. I think too that having spent so many years in schools, I have observed a lot of unspoken words in facial expressions. There seems to be no limit to the information a face can communicate and I thoroughly enjoy conjuring some of it up.
Most of my masks are one-offs, done in fired clay which has been tinted or painted. Occasionally I will produce a mold of the larger ones and recast them in plaster or winterstone. In this case, you will find a series number on the piece. All are designed to hang on a vertical surface