On the 25th through the 31st of October, post a journal/tweet/etc that's called LIGHTS ON. This shows that your "porch light" is on and you're accepting Trick or Treaters. People can come to your journal/tweet/etc and comment "Trick or Treat!" or whatever other code word you'd like to use. At which point, the creator of the journal can offer up small sketches or the like as treats for who comments. And, as to not overwhelm people, you can set a limit as to how many trick or treaters you'll take. Everyone runs out of candy eventually! Once you hit your limit you can change your journal to Lights off or closed, etc.