well hair has specific fits, and the same with poses, they are designed for specific figures, so I prefer to use the same system putting them under the figure that they are designed for, as far as other things if they are designed to fit people in general than yes perhaps a general folder under people though I will try to avoid that personally, I do use seperate folders for General Props and Environments though if a prop is designed for an outfit say, it really should go with the outfit.