Drop your feed dogs and be sure to stabilize the fabric.
If you are making French knots in several different places , it
probably would be a good idea to use a machine free motion embroidery hoop
(not the embroidery hoop that comes with your machine) to keep the fabric
stable.
You can use the candle wicking foot or the Q foot or no foot at all.
I use embroidery thread on top and the embroidery
bobbin thread in the
bobbin.