To make your own, you will need a mason jar with a lid and ring, some sort of fake snow or glitter, a hot glue gun (or regular glue), and something to glue onto your lid. I wanted to use bottle brush trees, but any sort of figurine would look neat. I would recommend checking out thrift stores or dollar stores to see what kind of small Christmas trees or figurines are available. Thrift stores are also a great place to find mason jars.
Next, pour in some fake snow or glitter. Use as little or as much as you would like; you can always dump some out or add more later.
With the hot glue gun, glue the tree or figurine onto the lid. Make sure that there is plenty of room around it so that the snow/glitter can move freely when you shake the snow globe.
Next, put the lid on the jar, screw on the ring, and flip it over. You now have pretty snow globes that didn't cost you $40! You could also add some festive ribbon or some natural looking jute or hemp to cover the ring. The possibilities are endless!