The best way to take care of a Christmas cactus plant is to keep it in a warm, humid environment with indirect sunlight. Water it regularly but don't overdo it, and fertilize it monthly during the growing season. During the winter months, reduce watering and fertilizing, and keep the plant in a cooler location to encourage flowering. You should also repot it every two years or so, using a pot that is just slightly larger than the previous one. Finally, pinch off the spent blossoms to encourage further blooming.