Stem cuttings are normally taken on succulents that have grown leggy overtime.
After you take your stem cuttings, you can place it in a glass vessel filled with water so the bare stem/nodes are submerged in water. You don’t want the top leaves to be in water. Place in bright indirect light, and refill water when it gets low.
Or, you can insert the cutting into a moist potting mix. Place in bright indirect light, provide higher humidity, and water when the top 2-3 inches get dry. Rooting hormone can be used if desired, but isn’t 100% necessary for cutting to take root.