Thanks, Mary. I'm about to start my next attempt & I will try doing the inner curves first this time. I also made my own pattern that took the design & widened it throughout to 1" (0.5" + 1/4" on each side), keeping the 1/3" spacing between. I just finished applying some wash away/peel away double sided fabric tape & can see if that makes any difference, but your technique makes perfect sense. I haven't done much bias work since my dressmaking days & forgot how tricky it can be. You do the same thing with dresses -- sewing the inner curves first. I'll give that a try.
Thanks for the YouTube suggestion, saf. I actually have watched her video. It's great for learning basics about curves. I have had no problems sewing circles, wavy leaves, stems & other curved lines. It's just this one spiral that sits inside a circle to form the inner part of a flower that is giving me so much grief. To be honest, I'm not sure the pattern was actually designed to accommodate needle turn for this flower. The pattern says you can do it, but since it's a spiral (mostly bias cut, but some parts are SOG), and it has to fit within another applique piece, I think there probably needs to be some kind of change with the measurements. Waiting to hear back from the pattern designer.
Off to try round #5. lol