Our supplies were an empty tissue box (yay, recycling!), a glue stick, some orange foam sheets (you could also use orange construction paper, or you could also have your child paint the box orange) and some green construction paper.
I gave Pierce a choice between drawing the pumpkin face himself or letting me draw it. He asked me to draw it, because he wanted the pumpkin to look just like Spookley. Once the face was drawn, Pierce glued the foam sheets and stuck them to the Kleenex box. On the top piece, we had two orange pieces, so we could tuck a piece of the green stem underneath for added security. Then we curled the green stem around like Spookley's.
This post linked with the Halloween crafts at Jdaniel4smom's blog.