#1 pet peeve for me...running out of bobbin thread in the middle of sewing, and having no other bobbins ready to go. New cure - having lots bobbins ready to go at all times. When I've got a few minutes, and lots of empty bobbins I just start filling them up. Basically I only use gray, black, off white, and white for piecing so those for are what I always keep on hand...about 5 of each. I do have this silly internal game I play late at night, I say that I can't stop sewing until the bobbin runs out - do you ever do that?
Do you purchase your thread by the spool or the cone? I purchase Gutermann thread in gray, black, off white, and white by the cone, so it makes thread for piecing a real bargain.