Here is some more info about my class with Sylvia Pippen at Empty Spools Seminars/Asilomar in Pacific Grove CA. I'm going to show you the process Sylvia taught us.
Here is the pinned-on, not-quite-finished appliqué-sashiko wall hanging that I started in Sylvia's class. I have some plumeria leaves floating down a stream.
To begin, we started by tracing the drawing of the flower we wanted onto tracing paper. We then traced that onto plastic mylar which is heat-resistant so we could iron on it.
We did a sort of "exploded view," so that each petal was independent on the mylar. The individual petals were carefully cut out so that the mylar was left intact. That allowed us to use the mylar to fussy cut the fabric for the individual petals.
For now, just look at the top two "flowers" on my mylar sheet above. As you can see, the top flower's petals are smaller than the middle flower's petals. That is because we needed a template for both the flower and the "lip" of the flower. The lip is the differently-shaded part on the edge of the petal. You can see in the close-up below the two different parts of each petal. (These petals are not sewn down yet, which is why there are a few rough edges.)
Look at all these petal pieces I acquired. I made two different sizes of plumeria so I needed lots of templates.
We used these templates to cut out our pieces of fabric, adding about a scant 1/4" around the edges. Then we used starch and a small craft iron to iron the fabric around the edges of the mylar. Note that this is heat-proof mylar, which doesn't melt when you iron it.
For the flower below I didn't need to make a separate pattern for the "lips" of the petals because I found the perfect fabric. It had nice curved, wavy striations going through it, so I fussy cut the fabric to get my flower petals + lip/edge all at once.
After the petals are cut and then glued together to stabilize them, they need to be sewn together. The main petal part gets appliqued to the lip/edge pieces. Sylvia introduced (most of) us to a thread called Invisifil, made by WonderFil. It is a very fine thread that practically disappears when used for hand appliqué. I'd never used it before, but I love this thread! All of us in the class loved it! That explains why a lot of us went over to the little fabric shop (specially set up for the Empty Spools classes) and bought lots of little "six-packs" of Invisifil thread in all sorts of beautiful colors.
You really should go over to SisterStitches blog, Emmaline Design. She made quite a few posts about our stay at Asilomar.