Amelia- Three of her stylish outfits: A crimson gown for evening attire, her lavender plaid trousers, jacket, and matching parasol for an evening of pyramid climbing, and her self-designed archeological outfit based on Turkish pants complete with her toolkit belt. And her journals.
Howl- His rugby polo from Wales. His blue and silver suit with the long, flowing sleeves from Ingary. His thesis on charms and spells.
Aziraphale- His sword. Non-flaming, since only he can make it do so.