Depending on the project I use large zip lock bags. You can buy really really big ones and most grocery stores. Sometimes... I separate components of a UFO into smaller zip bags or small boxes, but they all go into one zip lock that contains all of it. I even use a piece of copy paper to list the contents.. and put it face up so I can read it. That part has saved me from buying additional supply's because I forgot I had one for the project. If I use a backing or batting out of the bag I cross it off .