So these next ones involve black paint and stuff you have on hand.
First up. Got paper? Got crayons? Set the kids to work coloring while you enjoy a few minutes to pee with the door closed. Take watered-down paint (the consistency of water, very little paint) and have them paint over their crayon images. The result is a wax resist image that looks way spooky.
Next, and I know Goose looks like the saddest kid in the world and it's partially due to me informing her that she would be giving up her bongo drum (my budding Matthew McConahey? or however that's spelled) to make this project, a luminary.
Take any container and paint it with black paint. Wait for it to dry. Then use an awl or a nail (both of which I wasn't comfortable letting Goose use, so she instead got a pen) then punch an image out along a pattern traced on or freehanded.
Goose's luminary turned out great, though she got a bit overzealous in places and had two huge holes. We lit this with a battery operated candle so there was no fire hazard. Now Goose has a spooky nightlight!