The hardest part is deciding how you are going to group the colors.

Here I did a ROYGBIV thing, but I imagine you could organize by company number or some other way. I like the rainbow effect of this way though.

The Reason?
I find that often the floss as it looks in a neat bundle in my hand is not always the color that it appears to be when stitched on to something, or right next to some other color. This way I can make decisions as to what colors to use just by folding the fabric a bit.