Cut 5"-6" long shoots from your established Rosemary plant. You want to be sure to select the new soft, tender green shoots and avoid the older, hard, brown, woody stems.
Strip the leaves from the bottom half of your cut stems. It's important to keep them right side up!
Place in a cup of water ensuring that the water level stays below your leaves.
Dump old water and refill with fresh every day. This keeps the stems from rotting.
Be patient! It can take anywhere from 2-6 weeks to see your first tiny roots starting to form.
After you have a decent start to your roots harden the plants off for about a week and then plant in a sunny place with well draining soil.