Having a machine with needle up/down button is really helpful. Stop with the needle down on the outside edge of an appliqué for outside curves. Stop with the needle down on the inside of an appliqué on inside curves. This will give you good appliqué edge coverage. Use a stabilizer underneath to avoid tunneling of the satin stitch. An appliqué foot is helpful too because it has a space for the satin stitch to run underneath and it is open in the front so can see better. I think Craftybear listed a site this week that was on appliqué?