Trick or treat - no thanks
When I was a child "trick or treat" was an American tradition. Now I am an adult it has migrated to the UK as well. The problem is that the kids expect a treat (i.e. cash) in return for doing nothing whatsoever, not even fancy make-up and an imaginative costume.
Last year my local newspaper published a picture that you could post in your window to say "no thanks" to trick-or-treaters. I decided that with a few modifications the picture would not only say "no thanks", but that it would also enter more positively into the spirit of Halloween.
Here it is (and it works as well!):