Christmas cactuses are beautiful plants that make great holiday decorations. While they can tolerate a variety of conditions, they prefer bright but indirect sunlight and well-draining soil. Sugar water is not necessary for Christmas cactuses, and in fact, can be harmful to the plant. Watering them with plain, room-temperature water is sufficient to keep them healthy and hydrated. If you want to add a festive touch, try decorating the soil with red and green marbles or small ornaments.