I didn't do reverse applique. I did a machine version of Patti's quasi-needleturn method. We both had the same idea!
I appliqued a large patch of the yellow where it would be along the outer edges of the tiny ribbon. Then I trimmed out the back black fabric underneath the yellow patch, leaving about 1/4" margin all around. Then I appliqued another black patch that touched the inner edge of the yellow ribbon. Trimmed out the yellow from behind that! Then proceeded to applique everythign else. I think I have a pic of the back somewhere. I'll see if I can find it.