Well, one of the best ways to keep a cat away from the Christmas tree is to make it inaccessible. You can place the tree in a room with a door that can be closed, or you can use a baby gate to block off access to the room. Additionally, you can use some scents that cats find unpleasant, such as citrus, to deter them from approaching the tree. Finally, it's always a good idea to supervise your cat when they're near the tree, just in case they do decide to climb it.