Maybe...a skull or two with candles on 'em.
A hand of glory is always spooky.
Various bottles and jars of herbs, etc, maybe a mortar and pestle.
Dusty old wine bottles, goblets.
Dusty old books.
Scrolls with spells on 'em (for sale).
Rings, beads, trinkets.
Little bags for protective magic, other talisman objects.

(Personally I like the hollywood approach, but to each their own!)