Okay, so, this isn’t really a question I can answer because angel culture can look like however you want it to look like, and part of your job as a writer is to decide how you want it to look.
But… I know that’s not terribly useful advice, so I’m going to give you a few questions that can help you develop a culture for your angels when you don’t know where to start. Keep in mind that these are just starting points to get you thinking about angel culture. Culture is a large, complex, multi-faced thing so there are going to be a lot of things I miss out.
What do angels need to survive and how do they get it?
When I’m creating a culture the first thing I ask myself is: what do these people need and how do they get it? For humans this is food, water and shelter; and how humans get these things depends on the environment they live in. Now, think about what angels absolutely need and will not survive without. Do they need food like humans do? Then their culture needs to accommodate that.That mean’s they’ll either hunt, gather, farm or trade food. Each of these options leads to more questions? For example: if they’re farming what animals do they farm? Are they the same animals we eat or are they mythological? Or are they all vegetarians so only grow fruit and vegetables? What sort of agricultural technology do they process? If they trade, who are they trading with? What do they trade for food? How do they acquire that? Let’s say your angels don’t need food, but they do need something humans don’t need, like belief. If that’s the case then their culture will be structured around getting belief. How they would get belief (or whatever non-human need) would be up to you. You might come up with cultural rules/norms like every angel is assigned to a human to make them believe in them. Or maybe particularly powerful angels are sent to earth to preform miracles when belief starts to waver.
What physical attributes do my angels have and how could this affect their culture?
Make a list of all the things you already know about your angels and then think about what the logical consequences of a whole species having these qualities would be. For example: do your angels have wings? Then their building’s will have doorways large enough to accommodate their wings . Are they immortal? Then maybe they don’t celebrate birthdays. Are they genderless? Their culture is unlikely to be patriarchal. Are they created as fully formed adults? Then they probably don’t have a concept of childhood.
This is also a good time to think about how having magic might affect your culture. Do schools need to be fire-proof because of all the young children learning to control their fire-magic? Is it considered lazy to fill a kettle with magic , is it considered showy, or is it done without a second thought? It’s also worth thinking about the limitations and costs of magic in your world are. For instance, is it possible for angels to create massive earthquakes that would damage the world? If it is, what cultural rules/norms stop them from doing this? If your magic system has natural limitations, e.g. have to tough an object to set it alight, how would this affect culture? Would it be considered very rude to touch someone you didn’t have a very strong trusting relationship with, for instance?
What traits do angels, as a species, value?
Pick a concept (or a couple of concepts) that your angels value above all else. It might be something like personal freedom, family loyalty, democracy, athleticism, obeying authority, dignity, honesty, altruism, or originality. Once you know what your angels value you can start thinking about how their culture reinforces (encourages) this core value. This ‘encouragement’ could be positive (rewarding people for showing this value) or negative (punishing people for behaviour that goes against this core value).
Knowing what your angels value can help you make big decisions like what type of government their society has and what’s legal vs. illegal; but these values will influence the small things too. For example, it might influence the insults people use or what occupations have the highest wage.
What does power look like in angel society and who has it?
This is the time to consider what inequalities (if any) exist in angel culture. Is angel culture as a whole sexist, racist, homophobic, transphobic, classiest, ableist, ageist, etc? This bias doesn’t have to be overt - it can come through in the little things (microaggressions). For example, a society in which the majority of people assume a woman with a stethoscope is a nurse instead of a doctor is sexist, but in a different way from a society that bans women from becoming doctors. Once you know who has the power and who doesn’t, decide what privilege those in power have. Does power mean you can vote, go to school, own property, run for election, murder someone without any consequences…. Now consider whether power is something you can achieve or if it’s something you have to be born with. It can, of course be a mixture of the two. If power comes from wealth, then someone might be able to achieve power through hard work, but the majority of people with power might have still been born into it/inherited it.
How do the angels interact with other groups?
You mentioned that angel culture is distinct from human culture, but now’s the time to think about exactly what the relationship between angels and humans is like. Do angels purposely distance themselves from humans? Do they admire human culture from afar without interacting? Do they see themselves and superior and try and control humans with violence/threats. Do they see humans and ignorant children who need to be gently guided in a hands-on way? Did they used to have a close relationship with humans until one of they’re own was killed, and have now become withdrawn as a result?
How much cultural exchange is going on? Can humans and angels communicate at all? How common is it? Do they trade goods? What about services? Do they share new medical or technological advances? Do they ever discus politics or philosophy? Does one group try and force they’re political or religions ideology onto the other? Do they copy or adapt each other’s fashion or architecture styles? Is the cultural exchange equal or unbalanced? Perhaps angels can observe and copy what they like about human culture but humans aren’t aware of angels at all.
Also, assuming for a moment, we’re talking about an earth-like setting, which human cultures are the angels interacting with? Humans have hundreds of different distinct cultures. Are angels interacting with humans from 1850s America? Or 1850s India? Or both?
You should also consider whether angels are a monolith? Do all angels share the same beliefs, values and cultural norms. Or are they’re several groups/subgroups of angels that all have their own distinct culture. If they’re are, how do they interact with each other?
One final note…
There are a host of other things to consider when building a culture (technology, religion and art, to name a few) but hopefully this has been enough to give you some idea of what you want angel culture to be like. If you’re still stuck on how to develop your culture try answering some of the questions on the blog or feel free to send in anther ask and I can give you my thoughts on specific topics.
I’d also just like to add that you don’t have to know everything about a fictional culture to write about it. It’s perfectly okay to make up the details (or all of it) as you go along. Really. In fact, with culture being such a large and complex thing, I’d say it’s unrealistic to expect yourself to know everything about it.