Another experiment from a couple of years ago. Some of my hand dyed fabric stuck onto a fabric base with fusible webbing. I machine stitched over the joins using a normal straight stitch so that when I turned the work over I could see where the joins were. The fancy stitching was done by winding perle cotton onto my bobbin by hand and using an ordinary cotton/poly blend thread in the top. It was stitched up-side-down. My machine has a drop-in bobbin, and I just bypassed all the tension guides. I have no idea how you would do this on any other machine. I did a tiny figure of eight stitch (I don't know how else to describe it). The colours are brighter than this in real life.
Below, the perle cotton came out looking like a braid.
Below, the back of the work. This is what was on top as I was sewing.
At the weekend, I decided to cut it up into atc's and do some stitching on them. I got 15 atc's, I think.