Back when the children were very little I bought a pumpkin carving kit one halloween.  It had 12 quite complex templates for putting some intricate designs on the pumpkins.  It became an annual activity to sit down with the children and mark out the design then do the carving, and though I don't think we did all 12 patterns we certainly got through a lot of them.  The results were fab, it was certainly my favourite thing about halloween.  The children loved it too, though maybe they enjoyed dressing up and running around the streets in a big gangs, getting huge hauls of sweets, even more!