There have been many interesting ideas on drape molds here. One I've used and
haven't seen so far is to get a jar, like powdered tempera, turn it upside
down (for a larger surface), put a paper towel or napkin across the top (the
part sticking up), roll out the clay, cut it in a circle (or not) and drape it
over the jar. Makes a nice bowl. You can arrange the folds any way you want.
You do have to get to them before they start shrinking so they won't crack and
let them dry off the jars.