To keep a real Christmas tree fresh, there are a few things you can do. First, choose a fresh tree that has been recently cut and has a healthy appearance. Next, make sure to water the tree regularly to keep it hydrated and prevent it from drying out. You can also use a tree preservative solution to help keep the tree fresh. Finally, keep the tree away from heat sources like fireplaces or heaters, as this can accelerate the drying process.