I had the strips very carefully separated by width into small bags, but along the way, they got quite mixed up. That's okay; the idea is to take a strip and sew it on without worrying too much about your choice. I moved the bags from the sewing table to the floor at my feet so I can reach down and grab a strip as I need it. Seems to work rather well, as long as I don't get concerned about the mess on the floor. We don't have cats and Reggie, the corgi, rarely comes in here.
Here's a pile of completed blocks. 60 down, 84 to go!