The best way is by layering a stem into a pot or the ground and pegging it down till it is in contact with the soil an dthen wait till it roots which can take a season. For cuttings, you need semi ripe wood which you ct half way between two leaf nodes for the base and just above a leaf node for the top. Remove any flower buds and, if the leaves are large, one of the pair of leaves.
Place the cuttings around the edge of a pot of free draining compost such as John Innes mixed with extra grit. Push the cuttings down till the leaf node is in contact with the soil. water well then cover with a plastic bag or place in a propagator or cold frame out of direct sun. Be patient. It can take weeks for roots to form and the success rate is low.