To keep a live Christmas tree alive, it's important to provide it with proper care. First, make sure to choose a fresh tree with plenty of needles that don't fall off when touched. Second, keep the tree away from heat sources such as radiators or fireplaces, which can dry it out. Third, water the tree regularly, but don't overwater it. Finally, use a tree stand that holds water to ensure the tree gets the moisture it needs. By following these tips, you can keep your live Christmas tree healthy and thriving.