The Paleolithic people used clay. I like using brass in my artik ceremonies. Artik means welcoming the dieties. Offerings are presented by waving them in a circular motion to the deity's head, chest and feet. Put some music on while you perform artik , or have peple sing Goddess songs, play drums or cymbals.
Food is the first thing that is offered.
The Goddess likes to eat. If you are making a special meal, or are having like-minded friends over, make a plate for the deity and set it on the altar. My deity likes chocolate. Next offer incense. The traditional way of offering fire is with a ghee lamp.