OOps hit send to quickly. When you are ready to place the pieces onto the background. You will use "Liquid Stitch" (you get it at WW or JoAnns, etc) Make just a tiny pin hole in the bottle top. You want just a little bit to come out. Starting at the piece that will be the bottom of the design and run a small bead around the back side of the piece, about 1/8" from the edge. Then put down on the background. Hold for a few seconds, then set it with an iron. Continue till all pieces are in place. You can then hand sew the pieces down or use a small zig zag stitch. Use matching threads or you can also use invisible theread. I'd match thread to piece if doing by hand, but use invisible when doing by machine.
This method is kind of awkward the first time you try it, but once you have the hang of it, it works like a charm. Oh yes, when done, soak the block in warm water, the Stable Magic will soften, but stays in place. Good luck!
Sometimes LQS has Stable Magic.