To keep a live Christmas tree fresh, it's important to follow a few key steps. First, make sure you choose a healthy tree with vibrant green needles and a strong trunk. Next, place the tree in a stand with plenty of water and keep the water level up as needed. Additionally, keep your tree away from any heat sources like fireplaces or radiators. Finally, if your tree starts to lose its freshness, consider using a tree preservative solution to help it stay fresh longer.