I ❤ embroidery . . . Fishbone Stitch Video Tutorial~ The fishbone stitch is an easy hand embroidery stitch that works great for creating filled leaves and petal shapes. You can use the stitch for other applications, too, but the fishbone stitch is most often seen as a filling for leaves. This is because it creates a satin-stitch-like filling, with a natural spine down the center. The thread used for that leaf is cotton floche, a wonderfully soft hand embroidery thread.
Coral Stitch (How-to From We Love French Knots by Bari J. ) This makes a nice decorative stitch but can also be used as a filler stitch - more of a lazy fill stitch, though.