First, prepare the pots the cuttings will go into. You’ll need gritty compost, so add coarse horticultural grit to multi-purpose compost. Choose healthy young growth that hasn’t flowered this year.
Cut the stem with sharp secateurs just below a leaf joint to make a cutting 5-10cm long. Strip off the leaves from the lower stem, leaving just one or two pairs on the top. Dip the end in hormone rooting power or liquid and then pop it into the pot, a few centimetres deep. Gently firm in the compost and water well.