I used a wood handle bobbin and drilled two small holes for "hooks" to make a dubbing loop with thread while tying. Here is a video on the original "hook bobbin" I copied...
This video shows how the o-rings hold the thread stored. You can figure out how to make adubbing loop easily.
The other bobbin I simply added rubber o-rings that fit tightly to the brass cylinder on bobbin. You simply take your thread and run it between the o-rings to hold it while you add dubbing and spin.
The one bobbin without is just to see what the bobbin is like without o-rings.