Another process picture before I'm done -- just as a help for people who haven't started their pinwheels yet.
If you stack and attack the pinwheels construction as I did and then sew them as the top/bottom sets, then when you have chain sewn them, they will be ready to stick together in their left/right sides. So the top of the picture shows one of the pinned sets from the previous sets. Then is the sewn set, notice that I kept the chain stitching between them. Then you just fold them from that stitching, pin and sew the next seam.
It does take a little stacking and sorting and working with the concept to get it right. For me, the less times I move the fabric the less time I have to confuse myself. As we've found in this thread, I get confused a lot!