Adorable!
My thoughts are you want to make those Teddy's pop!
So I'm thinking a fine stipple or very fine cross-hatching for the background of each Teddy with an outline stitch close to the applique stitching of each Teddy. Also SITD for the rail fences. Then straight line quilting for the stripes in the border, the same width as the rail fence strips, and to create somewhat the effect of piano keys.