I haven't done a halloween party in years,,im too busy "haunting"
But,,,my mom really gets into it and has a big halloween dinner she invites people too. Each year is diff theme. Last year was "Mummies" so food had a mummy theme to it, they even had a stromboli she made to look like a mummy, that was pretty cool. Anyway, instead of bags she gives out favors she makes up that are themed to the dinner.
This past year since it was "mummies" she bought little tins that were rectangular shaped and decorated them to look like ancient coffins. Inside she put bone shaped candies.
Not exactly bags, but thought it might serve to help with ideas
Mike