A new product has been introduced this Halloween. Carvable artificial pumpkins. They look very realistic, made from high-density styrofoam. You can carve them just like a real pumpkin. Use tea lights to look like a jack-o-lantern or arrange silk flowers. I also recommend using a real pumpkin as a vase for cut flowers, but this is cheaper and will last year after year. You can find these pumpkins at most craft stores and some grocery and drug stores.
I've also used real leaves, protected with moisturizer, around this pumpkin - something I mentioned in this earlier post.