The rubber tree is also known by the Latin name, ficus elastica. It is popular house plant well suited to living inside under somewhat poor conditions. It usually grows with a single stem or trunk with large glossy leaves that grow directly off the stem. You can propagate a rubber tree by the process called air layering. It involves a few steps but is usually successful.
Cut a vertical slit into the stem of the rubber tree just below a leaf. Come up from the bottom and slice almost into the center of the stem, about 2 inches long. This is actually causing a wound in the plant.
Push a toothpick into the top of the slit, holding it open. This will keep the plant from healing the wound. The energy will instead be directed into forming roots.
Push some of the wet sphagnum moss up into the slit and then wrap it around the stem forming a ball. Squeeze it a little to remove excess moisture if it is dripping wet.
Wrap the section of plastic around the ball of sphagnum moss overlapping the ends forming a seal around the ball. Tie off both ends with the electrical tape to hold the whole ball in place.
Let the ball stay on the plant until you can see the roots through the plastic. Cut the ball below the bottom taped section. This is now your new plant. Remove the plastic carefully without disturbing the moss.
Fill a suitable plant pot with potting soil and make a hole for the root ball of your new rubber tree plant. Set the roots into the hole and firm the soil up and over it. Water when the top of the soil feels dry. Your new plant should grow new leaves rapidly.