I used to keep them in the clear plastic bins (one set of drawers and a few free roaming ones), but my new years resolution was to organize my stash (and craft closet), so I am in the process of wrapping all my fabric and storing them vertical.
I was SHOCKED at how many fabrics I had... then I thought I was truely done, and I found one more drawer, my Christmas fabric! Thankfully my hubby has been a trouper and continues to cut out the cardboard to wrap all my fabric on! They then go into a bookcase ($24 at Menards).
Happy stashing!