Both by dropping crappy things (cloaks of vunerability -54) and useless items (15 flasks of oil in the middle of the "main road" all enscribed with some stupid message (eat at joes).
Please, clean up after yourselves...and if you're going to leave messages, leave ONE item, and away from the middle of the street.
Also, Crimson, can we have more monsters that pick garbage up in town, but who aren't afraid of the bigger players? Perhaps monsters that can't be attacked, and don't attack players. If I understand how the game works, monsters, if grossly overmatched, will run away. That's great for in the dungeon, but in town it doesn't help if the cleaners cower in fear in one corner of the map.