holly leaves: back stitch with variegated floss, 3-ply.
stems: chain stitch using #12 Valdani pearl cotton.
heart: buttonhole with #12 Valdani
fern leaves: whip stitch only with wool thread. On small pieces like these, I apply fray block to the edges. As the name indicates, this will prevent fraying.
When the wool is dry, it feels hard to the touch, but the needle still glides through easy enough.
"Of all the trees that are in the wood, the holly bears the crown."