Some unique ideas here:
This site has lots of Christmas ideas using tomato cages. https://www.thekeeperofthecheerios.com/2016/10/tomato-cage-christmas-decorations.html
This can be a fun repurposed project! Turn the tomato cage over and tie the ends that usually go into the ground with wire. I wrap the tree in natural pine garland then add ornaments! You can also put it up on a piece of wood to look like a tree trunk. Have fun!
Here are some ideas: https://www.hometalk.com/search/posts?filter=christmas%20tomato%20cage&r=2
Here is a DIY http://everchanginggarden.ca/tomato-cage-christmas-tree-topiary/