I hate, hate, HATE those plastic bobbin boxes! Why? Because I always drop them or knock them off the table, and then my bobbins scurry off to the far reaches of my sewing space, unwinding themselves as they go.
My solution was to take a piece of garden hose that was 5/8 inch (16 millimeters) in diameter and split it lengthwise all the way down. The bobbins then snap right into the hose and stay very secure until I’m ready to use them, even if I drop it on the floor. The sides of the bobbins are always facing out, so I can easily tell what color of thread is on them. An added bonus is that the hose has a slight curve to it, which keeps it from rolling off the table.
If you decide to make your own, I hope you like it as much as I do!