Propagation from cuttings should be done as early in th espring as practical.. Simply cut a few healthy, leaf filled branches 8 to 12 inches in length with a sharp knife. Avoid using shears since they tend to damage the cell walls of the inner bark.
Place the cuttings in a container of damp sand for a week or two. Keep the sand damp but not water logged. Keep the cuttings in a sunny but not hot location. After the week or so place the cuttings in the desired growh location. If you wish to you can move them during the dormant season.
Alternately, you can take the cuttings in late aummer or early fall, place them in the same type of sand or even damp sawdust, place them in a cool protected place and overwinter, planting in th espring.
Several people propagate them simply by layering some drooping branches. Gently pull the branches down to a shallow trench and cover with soil. One can place a brick or handy stone for weight to keep the branch in place. It will begin to grow in place, again, after a few weeks.
Best o luck!