Chain Stitch is fine for lines, but also for fillings. I worked both this week.
Above is a flower with Chain Stitch only.
Leaves with three rows of Chain Stitch.
I like the combination of Chain Stitch and Back Stitch as in the stem. The little leaves are two Detached Chain Stitches.
Then a felted ball, with Chain, Buttonhole and Herringbone Stitch.
… and a denim swatch with different threads; Herringbone, Fly, Back Stitch and French Knots.