I love your wall hanging. Great job and great ideas.
I've made 2 crazy quilts and I'm still working on the second one. It's going to be wonderful when it's finished. What I did was use a square of muslin with the same size square of batting then I sewed the pretty fabric directly on the muslin (batting on the bottom). I then sewed and flipped the pretty fabric like someone else spoke of doing. I liked the result then when the block was all together I went back and did my decorative stitching. My first project was a bag. I got hooked on crazy scrap quilting with that bag but it is labor intensive. I'll attach a picture of the bag and block and the back side of the block..the bag is finished, the quilt isn't, yet! :>)
Good luck, keep sewing.
Randy