Since my pantheon isn't the greek one I can't give much information but as far as I know good offerings for Zeus could be: cakes,wine,incense,oak,meat etc.
As for the worship you should look into traditional pracitce of worshipping him or just have your own *UPG (or why not combine both).
Well, Poseidon being the greek god of the Seas, it would make sense to honor him with things of the ocean. Seafood as an offering? Seaweed, Sand dollars, starfish. Anything coming from the sea.
Ah Zeus. Awesome guy. I try to pray to him when there is a thunderstorm, which is almost always one in Fl, I only speak to Zeus Hades and Poesidon. As I have a conection with all three. Honestly, baked goods would be best. Or meat. I would offer him a cup cake. I'm sure even gods like those but make sure its made by you. Because your putting thought and effort into your offering.
In Ancient Greece pagans used mainly human sucrifices to show their respect. Since Ancient Greeks valued human life greatly it was considered a big sucrifice. When it came to human sucrifices they usually picked a king's daughter or wife. Moreover in ancient Greece they used to sucrifice animals for smaller requests.
Neo- paganism
Neo pagans usually worship their Gods and Godesses by sucrifising something that has great value to them or is expensive in general. However I would reccomend to burn something in your ritual that has great value to you and simply pray it could be anything as soon as it's not alive.
For Zeus you should also use incence (I would reccomend basil and laurel) and always keep something metal in your altar.
In general however Greek Gods appreciate sucrificies.
Moreover if you pray in Greek or ancient Greek it will also be apreciated.
Fox, where is the evidence that the ancient Greeks ever sacrificed humans? As for Zeus, females should be a bit careful of this Top God! He was a randy old God who liked to fornicate with human women! Bit of a Lad was old Zeus!
