|Oooh, ooh, I have one...Janie V's great tip on preventing tangling at the beginning of stitching reminded me that I just learned a great one for preventing tangling at the end.
I assumed that it was poor backstitching technique on my part that accounted for the occasional need to YANK the material away from the machine in order to trim the thread after finishing a seam. Actually what I was doing was sometimes not finishing a stich, resulting in thread going across the bobbin.
The solution: after you finish stitching (or backstitching) make sure you turn the handwheel towards you so that the thread take-up lever is all the way up, thus completing the stich, and allowing the bobbin thread to run free.
Credit for this tip goes to Linda Turcotte, who gave me my first sewing lesson last week, filled with all of these kinds of gems.