I just cut some pieces off the vine, and stuck them in a pot. Now I have 3 more plants, now I just have to find a place to plant them. Ideally a place where the squirrels can't get to them since they seem to like to eat them when they are ALMOST done.
Layering seems difficult but its easy. Fill a put with potting soil, place it next to the plant you want to propagate, and bend a branch under the soil. To keep it in place I usually just hold it down with a small rock. This is a very easy way to make multiple Salvia Greggii's