For satin stitching, a foot that has a wide groove in the bottom of the foot. This is the most important feature to look for when choosing a foot.
It can be the zig zag foot that comes with your machine, an open toe foot, or another out of your collection. Try out a few and see which one works best for you
I like an open toe foot for applique work, I can easily see where my stitches are forming :D:D:D