All Beliefs are Welcome Here!
I think it's a middle ground. What I mean is, there is the text which many religions get their basis of their Gods from. So the lore tells us traditional offerings that were received well that ancient people of the time gave. But some things from back then it's harder to come by or for one reason or another not possible to replicate.
We also have things no which we did not have back then. Like for example, a traditional offering to Hermes is strawberries. In PCPG many devotees think he has a sweet tooth, I tend to agree. So it is reasonable to give such a whimsical God candy, strawberry soda, etc.
Loki is also said to have a sweet tooth and loves fire. So a lot of Lokeans will offer little firecrackers and such. One thing I think is funny is to offer him a snickers. Hermes is the helper of man and Loki is helpful too but...how they go about it is completely different.
Loki can be much harsher and more chaotic. He also has a thing about knocking people off their high horses. So giving a snickers and saying, "damn Loki, you scure me!" seems acceptable. With a lot of Heathen Gods, using titles can be really hit and miss. So things like, "Lord" or "Lady" can seem kinda wrong. As one Heathen friend puts it, "we honor our Gods rather than worship."
But how you would talk to or what you would offer to one God would be different from another. Some Gods demand a higher reverence or respect. One person I knew who honored Zeus says the way she talked to Hermes jokingly she would never dare speak to Zeus that way.
I'm told Odin really likes his alcohol and none of that cheap crap. Giving him the cheap stuff will offend him. You also wouldn't offer Thor lipstick just because you'd offer it to Freyja or Venus. When you read the story about him having to cross dress, you understand how deeply offensive that is.
So it's not always acceptable to say, "but I meant well!" That doesn't guarantee it won't offend them. So getting to know them and putting thought and effort into what you give to them is important. If I am unsure, I still offer it and say, "tell me if you like it...heck, tell me if you don't like it so I know for next time." I also find it easier because the Gods I work with are also exclusively Greco-Roman.
Of those, I only work with ones I find to be more gentle, whimsical, patient, etc. But there are still plenty of ways to offend even them. I had one guy who offended Mars and told me of the angry hostile vibes he got from him. He just couldn't figure out what he did wrong!
He told me his situation as I was in the right place at the right time. Almost like Mars/Ares was telling me, "tell this fool what he did already." Basically, he tried to gain his help without having a previous history of working with the God, getting to know him, didn't offer him squat, etc.
This is another situation where Hellenistic and Heathen Gods work completely different. It's not just a difference between give wine to the Greeks and mead to the Norse, viking hats and animal pelts for one and chiton with laurels for the other.
No, this is a fundamental difference in how these Gods generally operate. Greek/Roman Gods generally require kharis. You build it through devotion. It's a bond, an understanding, good standing with them. Even then, you understand they are under no obligation to fulfill your request.
Heathens hold their Gods to a different standard. Their Gods are more likely to help them but require something in return. A male Heathen friend of mine asked Freyja for help with his love life. To fulfill his request, she asked him to hunt something for her.
So he did not require a bond, a business type relationship on the spot of exchange or payment worked just fine. But for this reason, how you treat them, what you offer them, how you speak to them, and what you expect of them, will differ based upon the Deity and pantheon in question.
Which is why when some Wiccans are of the mindset, "work with every God from every pantheon without reading heavily into their lore first"...I mean, you can do that. But it might not go well. Same with mashing all the Gods together and saying all Goddesses are really just the many faces of the same Goddess. You can do that if you want, it's your choice. But in doing so, you are offending them.
For example, the golden apple story in Greek. How do you think Athena would like being called Aphrodite? It belittles the situation. That or saying Ares and Hephaistos are the same. That is offensive to both of them considering Ares threatened Hephaestus to try and free Hera and win or Aphrodite. Then, Hephaestus later caught him in a net. So if you offer a net to Ares...probably a bad idea.
Something as harmless as a net could be offensive, all from not knowing the lore. Maybe give a wooden eagle to Prometheus...you know, like the eagle that ripped out his liver and sometimes his heart. I'm sure he'd receive that well. It's just a cool bird after all, no reason to be butt hurt. That or maybe set up an altar for Athena and Hephaestus or Athena and Poseidon.
Hephaestus tried to rape her...but I'm sure she won't mind. Poseidon and her have a feud from because she won the contest for Athens with her gift of the olive tree being what the humans chose to go with. Poseidon then creating a shortage of water there and raping her Priestess Medusa. But yeah, this is why not every God is compatible and not every offering is acceptable.