I will be making some necklace/ornament/snow-globe items this week. Putting tiny little scenes inside of glass domes that have a fitting on the for hanging from a chain or cord or hanging them up with a small hook. I also ordered in some snow globe shaped empty glass balls that have a wide opening in the base. I don't have any photos of those yet, still waiting for glue to dry before I can move them around. You can order the glass domes and globes from sellers on Etsy. But if you want them in time for the holidays you need to order them from a USA seller because it takes a long time to get them direct from Asia.
Tiny trees can be made from the pipe cleaners or the dental floss brush picks that are already shaped like little tree. The one in the photo below was made by doubling over a tinsel pipe cleaner than trimming it to a tree shape and cutting it to the height I needed. Of course you can put all kind of very small objects inside of the little domes and globes. Nice hobby activity for van dwelling as it does not require a lot of space or tools.