Glyphs - inscribed in portable items or on meaningful locales (such as carven pentacles)
Shrines - non-portable - offerings left may eventually charge the area. Many shrines are often built in proximity of ley lines.
Magical tools - items that have a function to the practitioner in addition to reservoir capacity. Many items obtain a magical charge through years of ritual use.
Eyes - Chlendi Tradition - Often the eyes of practitioners or magical creatures, they are preservers then enchanted for storage.