There are a few different ways to create a mannequin Christmas tree. One way is to use an old mannequin and decorate it with ornaments, lights, and tinsel. Another way is to use an old mannequin body and cover it with branches and ornaments. You could also use an old mannequin head and attach it to a tree trunk and decorate it as a Christmas tree. No matter which method you choose, the key is to have fun and get creative!