The plan...such as it is. The one I'm following (sort of) is the bottom right design. It is 1.2m square in total.
Beginning of the centre circle...about 30cm diameter
Detail of centre
Second circle added (it looks off-centre because of the angle), and more details added to centre circle
Close-up. Once I've stitched the third circle on, I'll go back and embroider and applique over it all, then the plan is to stitch it to a backing cloth with an all-over running stitch that spirals and curves over the whole thing. Don't know if I'll need any extra padding between this part and the backing, I'll see what happens when I get there!
So I really am just making it up as I go along, and probably making a whole lot of mistakes that an experienced quilt-maker would know how to avoid, but oh well...it may be unorthodox, but I'll work out something...it just might end up being the long scenic route!