Mine is sort of "where can I put it?"
Generally, the cat prints are together, the blacks and whites are together, the really big pieces are on a bed, the halloween fabrics are together, small blues are together.
Where indecision sets in: when a fabric would be appropriate in more than one stack/box/shelf -
Examples:
the black and white cat prints - do they go with the black and whites or with the cats?
the "holiday" (Christmas or halloween) cats - with the cats or with the holiday fabrics?
the orange flowers - with the florals or with the oranges?
etc.