Just make sure you're not doing a moromancy (a foolish divination) or a pseudomancy (a false or fake divination.)
Divination using footprints
Divination or magic involving fish
Divination using icons
Divination using teeth
I've seen -mancy added to many words to pertain to magic as well as divination. Necromancy, for example, is the well-known school of magic of villains everywhere (and occasionally heroes, as well, depending on the story...)
Tell me about the unusual magic your characters use.