Heading back is used to remove damaged ends or to encourage your plant to bush out lower down the stem.
Thinning, on the other hand, is used to rejuvenate plants that are overcrowded with branches, allowing light and air through to promote healthy growth and increase resistance to disease.
Whichever method you use, it’s important always to cut at a jaunty 45 degree angle which slopes away from any bud present on the stem and to leave a short stub in place.
Prune to roughly a quarter of an inch above a healthy node (the swelling on the branch or stem on which buds form) at your stub’s highest point.
The angle of your cut enables water to drain away, preventing healthy growth from rotting, while leaving a small stub prevents it from drying out without leaving enough material on the plant to cause infection and disease.