Wonderful skull o.o i have a question: i just buyed the super sculpey that you use but when it arrived it was hard and looked like dry and even if i continue to touch it with hand it is difficult to work with. Did it appened to you too? How can you have it so smooth and manageable?
unless it is completely dried out you can usually knead it a while and it will get soft by warmth of hand, and the mixing. You can add some oil (some people use vegetable oil, i have never tried that), I use Bioil from the drugstore, but only very rarely because I order from high turnover stores only and keep my sculpey in the fridge and packed in plastic wrapping.
the main thing is get yourself a stiff enough metal rod. steel of an appropriate diameter, at least 2 mm, will do. I find aluminum bends too easy, good for making figure armatures, but if you want something to work against, you need something firmer edit: or you can twist a coil of aluminum, sculpt clay around it, and bake. that should be firm enough