I usually cut just above the next node on the plant, and then trim to approximately 1/2 inch below the lowest node on the cutting (if there's more than 1/2" between nodes). With the fleshier scenteds, I usually follow regular geranium practice and let them dry briefly to encourage the callus. With the very slim-stemmed or woody ones, I don't. You may not need the hormone, but it probably won't hurt.

Good luck and have fun!