Well done, well said. I sometimes help with 4H sewing projects. No matter what machine, I tell them to hold the thread tails behind the presser foot when starting a seam, and there will always be at least one person with a fancy newer machine who tells them it is not necessary. Just as I sit down and settle in there is a call for me to see why a machine is locked up tight. The only thing I would add to Miriam's advice is "Don't try to use brute force to pull the project with the thread jam out of the machine. A gentle rocking back and forth as you keep tension on an end of the thread often helps. Gentle rocking does not mean take another stitch."