Hey Bettia -- Since I'm drawn to the shapes and layers of the pineapple to start with, I would just stitch in the ditch to accentuate the layers. On the 'quilt show' version posted above, the triangles appear to be folded over the strips -- I would NOT stitch that down for fear it would keep that 'floating' illusion from happening.
Good luck -- pls post a picture! There's a discussion topic somewhere (Main? General?) on how to post pix, but basically you click the "Attach Files" button on the same page where you type your comments. Don't "Preview" or you lose the attachments and have do it again. :wink: