I've made some progress with this clutch. Here is what will be the smallest size:
Since the ends of the loop are sewn next to each other, rather than stacked on top one another, it makes it easier to sew. When they are stacked it can get tricky if you already have a bunch of layers to sew through. If you want to add a strap to the Zip Pocket Pouches this would probably work really well.
The fabric is this Japanese cotton fabric: