Simple embroidery stitch that starts with a row of simple back stitches. With a blunt needle, the yarn is then looped through the stitches. This can be done on fabric, of course, but is also beautiful on knitted or crocheted pieces.
This is how you get really smooth, lovely satin stitches. Outline in split or chain stitch, fill in the area with chain or long & short stitches, and then do the satin stitch. The underlying stitches support the satin stitch and help it to lay smoothly.