Thank you everyone for such great responses.
I tried the method with the paper template (turns out I had some of those laying around!) - ironing them down drove me bonkers ... couldn't get it to work properly ... and I really don't have the patience for itsy bitsy pieces around a hot iron!
So ... i used a quilt as you go method, doing raw edge applique ... I found this website:
https://www.stitchedincolor.com/blog...clamshell.html
and did exactly what she did, except for the ironing ... and I think it turned out pretty good, here's a pic.
Now that I have a method that I like, I can make a "real one".