To begin, its best to use a good quality cutting soil or you can make your own by mixing approximately 3 parts peat moss with 1 part vermiculite. Remember that the most important thing is drainage…even a cutting of lavender DOES NOT like wet feet!
Once you have a good mix, fill several small terracotta pots and make sure to dampen well. Now poke one small hole per pot into the mixture about 1 to 1.5 inches deep. Next, using a sharp pair of plant shears cut a small branch off the lower half of the plant that is about 3-5 inches long. Make sure that the branch is soft and not woody. Strip the leaves off the bottom half of the cutting and place one cutting per pot. Make sure to cover the bottom part of the cutting with soil. There is no need to use rooting hormones on lavender cuttings.
Congratulations, after about 6 weeks you will have several new lavender plants! Now, you can move your new plants to larger pots or into the ground.