Hmm… Some things I can think of:
- Items from the Calling the Corners spell
- Specialty items from Deirdre, such as the AG books she found, the items she used for her Calling spell, the walking stick, scarf, etc
- Characters or elements of the Six Books Deirdre used to unlock the Little Red House
- Symbols for the various types of magiq (Illiomancy, Telemancy, some of the various guild specialties)
- The ingredients, creatures, and constellations from the various fragments
- Nods to some of the spells the Mountaineers did, like tea cups, origami boxes, blindfolds, lanterns, etc
- Elements of Neithernor, like the door to the Warren, the statues in the grove, books from the vault