Practical bits for the cut itself. Clean sharp shears wiped with alcohol. Cut just above a node, the faint ring where a leaf joins the stem, because new growth comes from nodes. Take a small proportion of the leaves at once rather than tidying it comprehensively.
And expect milky sap. It irritates skin, it should be kept away from eyes and pets, and it will mark your floor. Gloves, and dab the cut with a paper towel.