Fill a 3-inch pot with a potting soil consisting of one part garden soil, one part sand and two parts peat moss. Water the soil until it is evenly moistened.
Cut a three-segment portion from the tip of the Christmas cactus. Dry this segment at room temperature for two to three hours.
Push the cut end of the segment into the soil deep enough so it stands on its own. Submerge up to one whole segment in the soil if necessary, leaving the remaining segments above soil level.
Place the pot in a warm area where the cutting receives bright but indirect sunlight. Keep the soil moist to encourage healthy rooting.
Monitor the plant for new growth at the tips of the original leaf segments for new growth. The cactus has rooted once new growth begins.