I use the Pellon SF101 woven interfacing for almost all my projects. I have the circle attachment for my Bernina and wasn't really happy with it, but will try again with interfaced fabric.
I also recommend sewing slowly, trimming the seams with pinking shears, and running a blunt tool around the edge after you have turned the circle right-side out. I use the rounded handle of my white Clover seam ripper.