I used to make treat bags, a couple pieces of chocolate, a couple pieces of fruity candy, gum, a little toy, and a glow bracelet. I quit doing the bags, because it just takes too much time with having a young child and working. When I did it before, my kids were older, and I was a SAHM. I'll probably do it again someday, when our little guy is bigger, and doesn't want one or six of everything.
The last two years, we had Goldfish packs in addition to candy and glow bracelets, and small Halloween themed rubber ducks for toddlers and babies (counting on their parents to decide whether or not they were safe, they weren't the teeny tiny ducks).
This year, I wanted to order little stuffed animals for the kids who were "too young" for candy, but I didn't get around to it. It's probably too late, now, without paying outrageous shipping. So the littles are still getting candy that their parents will eat.
I did buy some gluten free Veggie Chips bags in Halloween shapes, in case we get some who request GF items. Other than glow bracelets and GITD fangs, it's just the regular mini candy mix, mostly chocolate that Menards had pretty cheap recently.
I saw several people buying the boxes of mini Oreos (30 pks per box) at Wal-mart. That's not a bad idea, IMO.