oh dear...indecision...

Thought I would play with my design on the whiteboard. Allie, to answer your question, yes each 15" square block would only have 3-4 pieces. This was because  (originally) I wanted the tatting in there.And yes, I was going to piece the tatting into the seams.(but which ones!!) I DO want the tatting in there, but I think that is another project now.
I am (more than) a little fixated on leaves. The white board is still my design, and it would actually be smaller than 60", so I could  fit a plethora of pieced and embellished leaves in there.
So thoughts:
A green pieced background, with simple green stitching on those seams, and then leaves pieced in autumn tones and embellished. They would be 3D, so stitched onto the quilt after they are complete. This allows some portablilty in the project too.
or
a black pieced background, and green seam treatments on the peicing, and then the leaves pieced in varoius colours (they would still be a monotone palette, one colour per leaf) but lots of colours.
Maybe a green background, with black leaves, embellished with the Sassa Lynnne threads, and beading and SRE.

While I would love your thoughts on any and all of these ideas, I am thinking out loud, and you get to be the fly on the wall. I think it will be fun to see where this quilt starts, and where it ends up. Feel free to comment, it all helps.