Take a 4–6 inch stem cutting from a healthy basil plant
Cut just below a leaf node
Remove the lower leaves from the cutting
Place the cutting in a glass of water with nodes submerged
Keep the glass in bright, indirect light
Change the water every few days
Wait for roots to grow 1–2 inches long
Plant the rooted cutting in moist potting soil
Water the newly planted basil lightly
Keep the soil evenly moist
Pinch the top growth to encourage bushier growth