I store my piecing thread like this - each spool and it's matching bobbins is stored in a little 2" x 3" zip lock bag from the jewelry dept. Then I store those in 2 plastic bins - the one is for warm colors, the other for cool. Embroidery thread I store in plastic cases. I try to keep them color coordinated in type, i.e. Sulky, RA. etc. but at the end of a big project, they seem to get all mixed in.