Let’s see…
You could greet them at the door with a clip board and “do survey.”
Note outloud costume, then ask age (after each saying, “Hmmmm” and nodding). Then start with a logical question like “3 Musketeers, Snickers or Reese’s Cup?” and wait for an answer.
Then ask stuff like (waiting for an answer and checking on the clipboard):
Caramel Apple, Chocolate-covered Banana or Grilled Onions?
Ketchup, Mustard or Pickle?
Coffee, Tea or Me?
etc.
Then, drop a candy in the bag and check something else off on the board.
Not very evil…I know, but I didn’t sleep well–gimme a break.