I think this post could easily be summarized by saying "not all pagans/witches are Wiccan," but I think what that really means can sometimes use some clarification.
The (Triple) Goddess and The (Horned) GodNot all pagans/witches work with/worship/acknowledge this pair of deities. Beyond that, not all pagans/witches see it necessarily to work with a male/female deity pair at all. Some work with a single deity, a few deities, maybe a few goddesses and a god, a a few gods and a goddess, whatever. Deities don't always show up in neat little male/female pairings, and it is not something emphasized in a ton of traditions. (And no, not following a male/female pairing doesn't mean that person is unbalanced, doing it wrong, or whatever else.) Heck, not all pagans and witches are even theists...
There are a lot of moon gods and sun goddesses who might feel differently. Some moon gods include: Khonsu, Iah, Thoth, Baal-hamon, Mani, Ay Ata, and Tsukuyomi. Some sun goddesses include Isis (her lunar associations were Greek in origin, not Egyptian), Sekhmet, Hathor, Saule, Ekhi, Etain, Sol/Sunna, Arinna, and Amaterasu.
On a similar note, I notice a lot of pagans putting a lot of emphasis on fitting everything into a male/female or masculine/feminine box, and well, again, not something everyone's going to be doing... but that's probably a whole different post for later.
Athames, chalices, pentacles, and wands... nope, not all pagans/witches use these. And since not all pagans use these, it goes without saying that not all pagans place these on their altars. And as mentioned above, since not all pagans work with the Goddess and God, of course not all pagans have representations of them on their altars. Different pagan traditions (and individuals) have totally different ritual tools, altar needs, altar layouts, and so on.
Pretty much all pagans are familiar with the Sabbats of the Wheel of the Year: Yule, Imbolc, Ostara, Beltane, Litha, Lammas, Mabon, and Samhain. These are hugely popular holidays. Many also know that sometimes these are known by different names... Lammas/Lughnasadh, Imbolc/Candlemas, Litha/Midsummer, and other variations.
What it seems some do not realize however (and you've probably guessed where this is going), is that not all pagans/witches celebrate this same set of holidays. In particular, reconstructionist pagans (be they Greek, Roman, Egyptian, or other) tend to have their own calendars, but other traditions of paganism/witchcraft may not incorporate the Wheel.
Also, among those pagans/witches who do follow the Sabbats, not all follow the Wiccan God/Goddess mythos. There are many ways to celebrate the Wheel.
It should go without saying that not all pagans/witches follow the Wiccan Rede. Heck, it's not even all that emphasized in some Wiccan traditions. The Law of Three is another Wiccan thing. Karma is not a universal belief.
No, we don't all believe in the Summerland. No, not everyone believes in reincarnation.
No, not all pagans and witches cast circles, call quarters, etc...
Gems, Crystals, Tarot, Runes, Pendulums, Auras, Reiki, Astrology...
Yeah. All those things aren't a part of every pagan's path. Not all pagans believe in astrology. Etc...
I could probably go on, but I think the point is made. Whatever one aspect you look at, it's not going to be universal among all pagans and witches. Except for like, breathing. All pagans and witches breathe. Probably. I don't know. There's probably one pagan out there who thinks breathing is for peasants and refuses to do it.