You cut below a bud horizontally. For best results cut with scissors or secateurs first to seal the cut and again with a really sharp knife just before you pot it. This cut is square. At the top end you either include the apical leaves and between 2 and 4 nodes depending on the plant or you make a sloping cut above a bud. You keep the cuttings moist until its time to pot them. Then you seal the bottom with Root!t Gel which contains auxins and then keep them moist and sheltered over the winter.