satin stitches are really just straight stitches made side by side; very close together but not overlapping. use satin stitch to cover or fill an area. stitches can go in any direction, but should be parallel to one another. satin stitch is a simple stitch, but it takes practice to produce smooth, even areas of color.
i like to use padded satin stitch for irregular-shaped areas. to make padded satin stitch, outline the area using back stitch, and then make a few seed stitches inside the area. now cover the back and seed stitches with satin stitch, using the back stitches as a guide. this will help give your satin stitches a more defined edge, and will give the area a slightly raised and smooth effect.