Here's a set of instructions for "carving" precise shapes into a pumpkin by knocking them through using a cookie-cutter and a mallet.
Place a cookie cutter on the pumpkin and tap firmly with a rubber mallet until at least half of the cutter has pierced the pumpkin's shell. (If the pumpkin shell is thin, the cutter may be pounded all the way through the shell.)
Remove the cookie cutter, using a needle-nose pliers if needed.
With a small serrated knife (or the serrated saw from a pumpkin carving kit), follow the pattern made from the cookie cutter to cut out the image, making sure to cut all the way through the shell.
(via Super Punch)
Carve Pumpkins with Cookie Cutters [freshhomeideas.com]
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.