So in some research I've done on Hekate (normally spelled "Hecate" in English literature, but "Hekate" apparently is closer to the original spelling, plus it looks cooler), it says her domain is of the earth, the sky (it was always either "sky" or "starry/night sky"), and the sea. Because of part of her domain being the sea, I was thinking of including some sea shells I have in an offering I'm planning on giving to/making for her. Is this a good idea or no? Does anybody have a lot of experience with her? Does anybody know a lot on offerings made to her? Are shells okay? I feel like they should be, but emphasis about her virtues and domains focus more on her associations with the Underworld, crossroads, and witches.
Most of Hekate's attributes focus on witchcraft and necromancy. Hekate isn't a Goddess, She's actually a Titaness. The only reason that She would have attributes to the sky and sea, is because of Her parents. But that doesn't mean She's all sunny days and sandy times. Originally, Hekate was unfavorable to Man, and the creation of human beings. So when I say She isn't a people person, She just doesn't like people. But don't let that derail you from establishing a relationship with Her. It can be hard work with a Titaness who doesn't really like humans.
Hekate is a titanes because she was the daughter of Perses and Asteria,another minor titans.So she isn't one of the first titans who were against the olympians.You can experiment to see if She likes shells but if you ask me I find shells more for Aphrodite or a sea deity like Poseidon.
Offerings to Hekate may be: wine,meat,pomegranates ,flame offerings etc.
The Tians ruled in the olympus before the actual olympians do.Rhea (one of the titanes) is seen as the mother of olympians,so the olympians (an exception is Aphrodite) are the kids of Rhea and Kronus.
I don't work a lot with Hekate,so you might experiment to see if She likes.