You can grow a Christmas cactus from a cutting. You will need to take a cutting from a healthy and established Christmas cactus, and then place the cutting in a pot filled with soil that has good drainage. Water the cutting regularly, but do not overwater it. Make sure the pot is in a sunny spot, and the temperature should be between 65-75 degrees Fahrenheit. The cutting should begin to grow roots within a few weeks. Once it has established roots, you can transplant it into a larger pot and allow it to continue to grow.