Mostly for this age I would skip the party and save your energies for next year. There is a very good chance they aren't even going out or if they are it is to a few neighbourhood houses and that is it. You can introduce the shapes of halloween - pumpkin, ghost, bat but stay away from any of the spooky side of the holiday. For a craft we made bats - I found a bat picture to colour and then traced their hands and cut from black paper to glue onto the wings of the bat. We will be making ghosts on Monday by tracing their closed hands on white cardstock - make the wrist area the rounded head and then the uneven finger length becomes the bottom of the ghost. Add black marker eyes - I do this part for them - then we run them through my laminator, add a string and they fly them around the house for awhile then we tape them to the wall near the door for going home. I do this one each year and parents like to compare their child's hand size year to year.