A ton of examples can be found here.
One quick example is this double - sided leaflet:
"A German leaflet that attempts to cause disunity between soldiers and civilians depicts an infantryman with his M1 rifle at the top, and a civilian factory worker with a hand full of cash below".
So this piece of propaganda was made to be delivered by Germans to the Allied infantry. How? I can't imagine that soldiers would just throw them at the other trenches at night without getting shot at, or that some undercover agents would be able to distribute them.
Usually a plane would fly over enemy lines and drop them out of the planes in a specially designed bomb that would open up and disperse the leaflets over an area. It wasn't always effective as you left a lot to chance like wind speed and the altitude in which you dropped the leaflet bomb.
Follow up question: Has there ever been any study done on the effectiveness of this kind of propaganda? I recall an account I've read once of soldiers on the Pacific front getting these and laughing at what they recognized was a last ditch effort by the Japanese.
