I started doing this last year, and it was successful.
Currently, I have 3 shopping bags of candy for the Trick or Treaters for Halloween. I started buying candy and other like items while performing gas station mystery shops.
Sure, it sounds cheap of me to do this - but why not?
I can just imagine their surprise when one of the children receives a full sized Snickers candy bar (thanks Circle K) or maybe a double pack of Reese's Peanut Butter Cups ot maybe Blow-Pops or a full sized bag of M and Ms.
We really do not get that many kids, but, for those who visit our house, they'll get some pretty good stuff!