If someone's pronouns are any/all, what should I use or how should I determine how to refer to you and what pronouns to use?

if they say they don’t care what pronouns I use for them

I'm taking it at face value then and using whatever I think is appropriate. There's no point in wasting time playing games with this.

If someone tells you they don't care about pronoun usage, believe them. I'm nonbinary and don't care what pronoun people use for me, because I identify as both male and female. Most people default to "he" for me because of my beard, but others use "they" because of my proclivity for wearing skirts, nail polish, and lipstick. Rarely I'll have someone use "she" (or I'll use it myself), but ultimately, I'm just a person who exists outside of the gender spectrum (or right in the middle), and pronouns are just a grammatical tool to save time, so I prefer that people use whatever comes most naturally to them.

As someone whose pronouns are any/all I genuinely don't care, I'm not going to be offended if you pick one pronoun and stick with it - I am lazy and present male, being AMAB, so people default to he/him anyway - or just use the first one that springs to mind everytime you refer to me. Obviously I can't speak for everyone who is any/all but I imagine if most people cared they wouldn't go with any/all

As a nonbinary someone who accepts any/all I would say whatever comes naturally or is your preference. I've identified as agender since I was young and so personally I don't really like defining myself to other people in terms of gendered language. I would say if someone tells you their pronouns are any/all to trust them that they are actually fine with that.

I'm probably the least qualified person to comment on this, but I would probably just default to their name.

That's Bob's coffee

Those are Sarah's keys.

Less chance of fucking it up, IMO

As someone who doesn't care what pronouns you use, use whatever feels natural for you to use. My lack of care is just that. It's not some 4d chess to push the effort onto you. I'm fine with whatever, so refer to me however feels right to you.

I'm tomboyish queer chick, probably wouldve seriously considered transitioning if born in later decades. Get called sir, man a lot. Doesn't bother me. I got used to playing mmorpgs, everyone is assumed to be male, I never took issue with it, sometimes had fun with it.

My understanding is... if you're a minority with special requests. You're gonna know people might be confused. Don't judge harshly. Give people a chance to understand. If you want to be referred to a certain way, it's up to you to say that up front. And be prepared not everyone will be receptive.

I'm not speaking for everyone, or people wanting any, all pronouns used. This is more for the people wanting to accommodate, worried they'll offend.

The pronouns you use don't affect who I am, they simply express your perception of me. I suppose I'm just an asshole who doesn't care who or what you think I am. I know who I am regardless of what you say. Call me whatever makes you comfortable.

As an enby myself, I’d probably default to they/them but try to sprinkle in gendered pronouns when I saw them presenting more one way or another.

Depending on how close your relationship is, you can ask them if they have certain times that they prefer particular pronouns or not.

literally anything. call me whatever u feel like

"They" is perfectly acceptable, in fact I've taken to writing work emails as such too. Because you can't always work it out through their name alone.

The real problem is not learning or correcting themselves when told.

"This is Alice, she...".

"Oh he is a nice pers...".

"She, mum".

Be open to correcting yourself when told, people are used to correcting people. But continually not correcting yourself makes you look like a bigot even if you don't mean it.

I'm a man, I give my pronouns as any/all, because I'm comfortable with all.

I have a coworker who only uses feminine pronouns for me, because that's what she uses for everyone, including herself. She is also a man. I also use feminine pronouns for myself sometimes, eg. when quoting something I find analogous to myself that was written using feminine pronouns.

Obviously both male and neutral pronouns are fine as well.

Gender is a social construct, and IMO most men who get offended by being referred to by feminine words do so because they really believe being a woman is lesser to being a man. I'm not about that.

The answer is going to vary from person to person and the easiest way to find out is to just ask. If you don't know them well enough to feel comfortable asking, my two cents as a trans person is that I generally hold the same view as Leslie Feinberg:

I care which pronoun is used, but people have been respectful to me with the wrong pronoun and disrespectful with the right one. It matters whether someone is using the pronoun as a bigot, or if they are trying to demonstrate respect.

I've never understood the fuss over pronouns, because if I'm talking to you I'll refer to you by your name. And if I'm referring to you in a conversation with someone else, I'll refer to you by your name, but if I used any pronouns you wouldn't hear it anyway. 🤷

Just go with whatever gender they more come off as to you so you don't get confused.

they them is basically always safe! If someone specifically requests against it then don't but they/them is what I always use if I don't know or have multiple options. All I might add is that a lot of queer people get tired of being only called their AGAB's pronouns, so maybe don't exclusively use those.

This pronoun obsession is a distraction from real problems.

My pronouns are big/chungus

Yes, you are wrong. "Any" means you can arbitrarily choose whatever you like without them being fussed. It does not grant you (or anyone else) the power or responsibility to choose a gender for them.