A friend sent me the link to 'How to make Accordion HST's' and it is too good to keep to myself. Here is the link to the first of 3 YouTube videos.
https://www.google.com/url?sa=t&rct=...oHz8zRwNiyxncw
I had only one problem with the technique--my quarter inch foot sews to the
left of a line while the demonstrator sewed to the
right of the line. So I had to do everything backwards. But it does work! Definitely worth checking out.