How about one of those under bed storage tubs on wheels? If your bed is too low you can place bed risers ( sold at Walmart) under each leg of the bed. Great for fabric storage as well. I have quite a bit of thread stored in plastic carrying cases. Each case has different types, for instance, I have all my Aurifil in one, small spools for taking to classes and workshops in another, cones for quilting in one, and orphan threads in another. I hung my serger threads on racks behind the door. HTH