Being the kind of person I am I don't overthink it too much and follow exact instructions but apply the general principle of hardwood cuttings to gain more herbs like rosemary, lavender and sage. Below follows how to do it using Rosemary as an example.
This is mother rosemary. It is a huge plant that stands under my bathroom window and has been growing for about 7 years in this spot. In summer it has delicate purple-blue flowers that attract the bees. While we use rosemary in cooking a few times a week, and don't really need another plant, I have wanted to have a bank of rosemary buses at the pond garden for bees and beauty so have been making baby plants from this one.
Every time I use rosemary, I simply cut the length I need from the plant and strip off the lower leaves to use in my recipes. The remaining stalk gets added to a glass of water with others and stands on the kitchen windowsill. I refresh the water when needed - a couple times a week, generally.
After a few weeks these new roots begin to appear. I wait until the majority of the stem is covered with them before planting them into a smallish pot containing a rich compost potting soil mixture with some added coco-peat.
This baby rosemary bush was planted in November and has set itself nicely to the job of growing up. I will transplant it, and its siblings, in a few weeks around the pond.
As we often need sage for soap, cooking (it's superb with pork) and for the chicken liver pate that my daughter makes and sells, I have started propagating that delicious herb too. Lavender is also useful for attracting bees, making soap and for the sublime honey and lavender ice-cream I have made before. Lavender is also just for aroma therapy when walking through the garden.
Do you propagate herbs and plants from cuttings? Tell me about it! I love to learn from your comments.