So you take an album cover...remember vinyl albums? Anyway you take shit...yours, your dog's, whatever. Put it inside the album cover. Make sure the shit stinks bad (preferably with decoative corn) and that it is in the album cover far enough to where the opening of the album cover is closed.
Slide the opening of the album cover under the victim's front door and step on the album cover, from the bottom to ensure ALL the shit comes out of the album cover. Kind ofhow you would squeeze tootpaste from the bottom upwards.
Remove the album cover & leave. Chances are that he victim won't even see it until they've smeared it all over when they open the door!