Here are some pics of the back of my postcards. As I said, I did them similar to the ornies in the CQMagOnline article, however, I only pressed the seams, rather than stitching them to later fold along.
Once the postcard is embellished, I use my template to cut out a piece of Heat'n'Bond. This is double sided fuseable *stuff* and it quite stiff when it cool, so it is ideal for postcards. Once the heat'n'bond is cut out, I fuse one side to my backing fabric. check it for size, trimming it to slightly smaller than the postcard, peel off the paper, and fuse to the postcard and we are done!
As I said previously I cannot use the buttonhole stitch effectively, so this works well for me. The back seems to be stuck on really well...but heck, if one of you gets a postcard with no back on it, well you know its from me ! *smile*