I like to have a lot of options in my settings for religions and belief systems. In it, I have totems which are a spirit animal, plant, or concept that protects a clan or a tribe. You have your family's totem, your tribe's totem, and can have your own personal one that reflects something that happened to you. Maybe a wolf sparred you while out in the wilderness and now the wolf is your totem.
There's also tonali, which are spirit animals tied to the deities in my setting. Each deity has a month and each month has a tonali (except the last five days of the year). So the month you are born in gives you your tonali. Though for divine casters like clerics, this can be ursurped by your patron god's tonali. So if you were born in the month of the caracara, but you worship and serve Tezcatlipoca as your patron god, then your tonali is the jaguar. The high chief's tonali is interesting, as it begets a cult that reveres their tonali as a powerful god of their nation. Even the main deities have tonali, which are revered by practitioners of tonal.
Then there are local gods called zemi. Spirits that are petitioned by shamans for wisdom, magic, and guidance. Every household, location, and city has a zemi that guards them. And then there are hero cults for different chiefdom's histories. Founder's myths, great military leaders, all can be worshipped though more commonly they are respected and evoked in times of great need. There's also ancestor worship, where people can evoke their ancestors for guidance. Some ancestors can even be a family's totem.
Finally, there are the gods. Everyone prays to all of the gods, even the "evil ones". The gods themselves are above alignment, but some do tend towards more benevolent or malevolent attitudes (like the goddess of healing vs the god of slaughter). Many of the more malevolent gods are prayed to by people out of fear, beseeching them to spare their city or loved ones from their wrath. Although many of the malevolent gods also hold sway of some everyday dominion. The goddess of murder, for example, is also the goddess of secrets and many pray to her to keep their skeletons in their closets. The god of tyranny and darkness is also the god of wealth, with everyone praying to him for great wealth and fortune. So there are no banned gods, just banned antisocial cults that disrupt the stability of a city. It keeps it more "real" for me that all the gods would be prayed to.
People can also pick their patron god. This is rare amongst the common folk and more seen with servants of the gods, like clerics and priests. High chiefs will pick the patron god that they feel best reflects their people, or shares the same tonali as them, solidifying their divine right as ruler.
For me, there are some non-negotiables when it comes to the big deities. Unlike the previous local gods and hero gods, these are cosmic forces. So, they don't die from old age and in terms of deicide, are hard to kill. So most can be imprisoned for eternity. Gods can be killed, but one killing the other would ignite a terrible cosmic war that would probably end with the destruction of most, if not all of their work. And all of the gods like the universe they built, even the more malevolent ones. Plus, it's a taboo, like killing your kin. That's why the gods act through worshipers, champions, and servitors. When a local god or spirit guardian is killed, it's not a big deal (cosmically, that is). When a big deity dies, a fundamental aspect of the universe changes or disappears completely. That's up to the being that does the killing.
I also have it that gods do not need worship to remain powerful. I always found it weird that gods create races and whole galaxies, but need the power of belief to exist. Instead, worshipers provide them with souls in their realm. These souls can be made into servitors, guardians, and champions that can act on the god's behalf. I haven't figured out what sacrifices do yet, but I do know I want people that are sacrificed against their will to be less beneficial to a deity than those who are willing and wish to be sacrificed.
Roll that all in with numerology, vitalism, astrology, reincarnation, and you've got how varying religion is for my setting. That also doesn't cover the growing philosophies and the other religion, a monotheistic religion inspired by gnosticism. I really like religion and enjoy the great varieties of worship one can have.