Strawberries can be propagated by seed or by using runners.
From seed
Collect seeds: You can rub the skin of a dried strawberry, peel the skin off a fresh strawberry, or use a blender to separate the seeds from the fruit.
Stratify the seeds: Wrap the seeds in tissue paper and put them in a sealed container in the freezer for 2–4 weeks.
Plant the seeds: Sprinkle the seeds into moist potting mix in small pots. Cover with a thin layer of potting mix and place the pots in a warm, humid environment.
Grow the seedlings: Once the seedlings are 2–3 inches tall, separate them and move them to individual pots.
Care for the seedlings: Place the seedlings in a bright location, but out of direct sunlight. Water them regularly and feed them with a balanced fertilizer twice during the growing season.
Harvest: The first harvest from a plant grown from seed usually takes place in the second year.
From runners
Find runners, which are wiry offshoots that grow from the main plant.
Cut the runners off the main plant. Fill a small container with well-draining potting soil. Pin the runners to the surface of the soil. Place the container in full sun and water regularly. After a few weeks, the runners will be big enough to survive on their own. Cut the runners from the main plant to create a clone.