In cross-stitch, often the backstitching can bring a piece to life. In quilting, blanket stitch can do the same for fusible appliqué. I love choosing colors to either blend in and enhance slightly just to reinforce the line or give a nice contrast and really pop!
(Just ignore the stray cat hair or piece of fabric/floss – those are pretty much everywhere I live and work).
Fun! Always enjoy your applique.