While the larger images are usually your inspiration and set the theme of the piece, it is those in between bands that can add a lot of interest to a design.
In designing Northern Nights I began to see that the narrower bands reminded me of something else from my quilting days, a favorite fabric, ticking! Not just the simple ticking of pillows and mattress coverings, but decorative fabrics that were made up of rows of varying types of stripes, many resembling ribbons.
Here is a lap quilt I made years ago and you'll see the block of fabric that displays this ribbon quality.
If you take a close then distant view of different patterns in your designing palette you'll find quite a few that can be cut from a larger whole and then repeated to form something that can give you that ticking/ribbon effect. You can add tumbling flowers or geometric shapes that can bring that sense of movement to your design.
Placed between your larger bands for division and symmetry, those 'tweeners' can really affect the overall design.