welp, me and my friends just ran around the elementary school, haha. No one trick-or-treats anymore, so no one to scare.
I'd say get a bunch of random supplies and make costumes together, then go run around the streets in them! Possibly make goody bags for trick-or-treaters... do scary makeup on each other!
I really can't think of anything too scary... maybe making decorative masks to hang on your walls?