I would take a semi-softwood cutting from a side branch that the leaves aren't too far apart on, with three joints. Take the lowermost pair of leaves off, and immediately dip the lower end into rooting hormone powder, and insert it into a moist rooting medium of equal parts sand, perlite, and vermiculite. I would start several cuttings to be sure of getting at least one healthy start. Put the pot with the cuttings in a plastic bag, and punch a few pinholes to let in oxygen. Put the covered pot in a warm spot, in bright shade. After two or three weeks, new growth should start coming out of the exposed joints, and that is an indication that there are new roots growing. That's when you gradually start exposing them to more light and air, to harden them off. Once they are used to the "great outdoors" again, you can gently transplant them to small pots of all purpose potting compost, and give them a light feeding. By spring, they should be ready to plant out in the garden.

You could also layer it in the Autumn.
Annie.

Anne's right, and that actually might be easier, though it would take longer.