I use heavy duty wire cutters or bunch cutters to cut the woody stem off to the right length. I rarely use my knife on thick, woody stems. They quickly dull my sharp floral knife, making it easy to slip and cut myself.
Use the right tools for the job. That includes guarding your ribbon shears! Don't try to cut flower or greenery stems with regular household scissors. It dulls them quickly making them useless and can actually crush delicate flower cells in the stem so they can no longer take up water properly. Always cut flowers with a floral knife, floral scissors or bunch cutters. The one sided sharpened blades are designed to cleanly slice through stem cells without crushing them.
Now I place a second, shorter lateral of the myrtle to curve off to the left. Tape into place.
I add another stem of leather, beginning to make them shorter as I move down the taped stems.
Don't forget the back side. Conceal the "wrong side" look of the ferns with enough ferns facing outward that the final bouquet will look good from both front and back.
Now my taped greens are ready to begin adding the flower stems.