Well, perhaps we could look at a way to make things "decompose" that would help littering. Naturally and food would be either decomposed or scavenged by another creature. Or perhaps some metal ore would gradually fall apart from wear. I am saying that could we not make it that when dropped items gradually degrade in quality until they hit -1? (-1 since there are so many quality 1 items that they would decay insanely fast if they only had to go to 0.) That way items such as food decay quickly, and items that are more valuable, such as high quality swords, tend to last longer. I also like the waste basket idea, I thought about suggesting it but it would seem complicated on how exactly it would be in the settings.