Thanks for the suggestions. If this had been a larger quilt, I would definitely have used them.
But because this was just a little doll quilt, I ended up wimping out. I just stitched in the ditch around the windmills and quilted straight lines in the border which were parallel to the edges of the closest windmill.
I have to admit that even following the "ditches" turned out to be challenging. If you don't keep your mind FOCUSED, you end up wandering all over the place, and then have to figure out what you missed by looking at the back of the quilt. (Guess how I know this??)
BethMI