By non-magical I mean objects that aren’t made of magic, doesn’t rely on magic to operate, and won’t produce magic, so things like Amity’s training wand, an abomaton, the portal door, crystals balls, or Penstagrams are off-limits.
I would pick Amity’s moon necklace, Lilith’s “I was sacrificed to the Grandhuntsman” t-shirt, and Willow’s scrapbook.