If your artificial Christmas tree is looking a little flat, there are a few ways to fluff it up and make it look more lifelike. One option is to gently shake the tree branches from side to side, which will help to distribute the branches and create a more natural appearance. Another option is to use a tool such as a Christmas tree comb, which has prongs designed to help separate the branches and give the tree a fuller appearance. You can also use a hairdryer on a low setting to gently blow air into the branches, which will help to loosen them and give the tree more volume.