Sweet Paul's gorgeous snow globe we had to make our own! We too used rock salt but added a touch of glitter. With a miniature tree I got at a sale last year we just poured in salt, added glitter, popped in the tree. I already had the jar which I bought at the dollar store and use for a vase. The jar really needs to be wider and taller for this size tree - I'll hunt for a better one for next year and an adorable deer.
Oh and the tree was with the model rail road stuff in the Christmas warehouse!