When I was teaching for the Sew Broke Quilters in Mars, PA, one of my students had these nifty bobbin holders. They are made from squashy rubber and are a very handy way to keep a bobbin with the corresponding spool of thread. I think they are ingenious and am ordering some. Once again, I was introduced to an awesome new gadget during a workshop.
Here’s a YouTube video from the makers, Smartneedle Inc. These bobbin holders are available on Amazon and cost $9.99 for a pack of 12, (no shipping charge if you have Amazon Prime).