Iron them onto small pieces of fabric that have been cut a little larger then your Wonder Under piece.
Now cut them out.
Ok, from here on out, sorry, no pictures I got too excited and forgot. But it's pretty self explanatory. Iron your pieces on to the background fabric starting with number one. Iron them as close together as possible. Now choose a stitch that you like on your sewing machine, (zig zag or the blanket stitch works great, I don't know what the stitch I used is called but it worked really well also). Start with the stitching the areas where the two fabrics come together and then stitch around the outside! You can click on my picture for a better view!
Then I just went to the local craft store and bought a frame (I'm wishing I would have bought one with a thicker frame but oh, well). I also had them cut me a mat to the size of the frame and then I stretched the fabric around it at stapled it. And WA LA, you done!
If you have any questions feel free to leave a comment, I will answer them in the comment box too, because to be honest, I am to lazy to e-mail! One more thing, if you end up making this, e-mail me a picture, I would love to see it.