A real sewer can do them better but here's how I did 'em:
Very carefully measure the stitched design and border; add 1/2" for seam allowance. Cut the design, a piece of thin batting, and bottom fabric to that size. I wanted a mat-like effect so I added an inch to those dimensions for the bottom fabric sandwich.
Place the right sides together; make sure that the batting is the lower most layer. Being unable to sew straight lines, I used an air erasable pen and drew where I thought I should stitch on the top most layer of each part. Make sure to leave an opening to enable you to turn the sandwich right side out. Snip extra fabric and clip corners .. Do the turning thing and press. The opening can be sealed with stitch witchery if you're not a good invisible stitcher.
Place the two pieces one on top of the other; turn down the top corners of the first layer to make a triangle and then overlap this with another triangle from the bottom layer. Fasten the corners with buttons. I'll let someone else jump in with a good way to add ribbon or cording for a hanger.
The hardest part for spatially challenged, klutzy me was getting the squares for each sandwich to be the same size.