Thank you! Sure, I have some tips I guess(?), haha, since I've been publishing fic for over a decade—here is a list in no particular order that I have not established prior and am just making up on the spot:

1) Write for yourself first!!! Instant validation and "popularity" is easy to get sucked into (especially when fandom these days is primarily on the same social media sites—namely Twitter and AO3, where numbers are both visible and relevant to how people learn how to find new content, unfortunately) that if you're an anxious person like me, it's easy to get stressed and bogged down by just the awareness of it. So I would say that first and foremost write things you want to write, OR things you want to read. Whatever makes you happiest at the moment. I used to write a lot of things that were "easier" for me to write but not necessarily what I wanted to read, which was fine for me at the time. But these days I'm much more focused on writing things that I want to read! So I think just figuring out what kind of person you are, what kind of writer you are, and how you want to write things regardless of numbers or feedback is one of the most beneficial things you can learn as a fic writer.

2) Read a lot! I'm assuming maybe you already do this since you found my AO3 by reading my works 😅 But I think this is something that a lot of writing-focused writers, both in fandom and out of it (cough cough for anyone who knows what's been going on in booktwt lately), forget to do—that reading is as fun as writing, if not more. Even if you don't know a fandom, or have no interest in writing for a fandom, reading for it could be really fun then—maybe even more than for a fandom you are writing in (or know anything about if you're picky about characterization.) Reading allows you to both enjoy yourself in getting enraptured by other people's ideas; and, whether consciously or not, can also help you study the craft—either writing itself or fanfiction in particular (which I consider a separate genre/writing style from original writing or published novels). For example, I've gotten a lot of compliments on how "realistic"/"in character" my dialogue is, and I think that comes from how much I've read, seeing the way other people write dialogue, and how to transpose similar schools of thought into my own, even if the characters are completely different. And I didn't do this consciously! Just after a while, it's something that's become natural to me.

3) If you're writing in English and it's not your first language, or spelling/grammar/punctuation isn't your strong suit, either get a beta reader or just take some time to learn some basic writing rules. I don't say this because I'm a stickler—although I am—but because the whole purpose of knowing proper spelling/grammar (or doing the best you can at it) makes it easier for people to read your writing; it makes your writing more comprehensible. People don't want to read things that are hard for them to read, especially in fandom when people are just trying to enjoy themselves! I've gotten criticism for complaining about inaccurate grammar/punctuation before (because people "don't respect the English language" or whatever) but I think that just goes to show how people don't realize that this is why we learn spelling/grammar in school. Even if it's not perfect, the slightest amount of effort to learn the most comprehensible way to express what you're trying to say can go a long way.

Additionally, paragraph breaks are your friend :)

But yeah, I don't think beta readers are necessary for fic if it's not something you're comfortable with or it's just uncharted territory that you'd rather just post your writing raw first. Especially for first-time writers who don't quite know how they can handle more critical feedback yet—it may be more beneficial to allow yourself some mistakes when posting, until/unless you eventually get more serious about writing. But I know not everyone is, so I'd just say learning basic writing rules and studying a bit on your own should be good enough (and sometimes this studying is done subconsciously—see what I said about reading in point 2 😊)

4) Look for fandom events, whether on AO3 (creeping through people's collections or bookmarks), google searching [fandom/pairing] kinkmeme or exchange or big bang or fest, or on good old social media (see what I said about googling), especially if you want to meet other fans or want to write things for other people or you just want ideas to practice writing! One of the first things I did when I really got into writing/publishing fanfiction (Super Junior 2009... good times) was that I found this 30-day prompt challenge and used it, even though I don't think I officially signed up for it, nor did I post any of the works publicly. But I made myself write one prompt a day, no matter how short (some were 100-300w long) and it was a great exercise in writing, if not anything else. I think fandom events are also a good way to get your fic out there because many people like looking through all the works for a fandom event regardless of who the creator is, and are thrilled to find new writers that way! So if social relevance IS something that you're interested in regardless of what I said in point number 1, this would be a great way to do it 😄

5) Don't put "I'm bad at summaries" in the summary, or "I'm bad at tagging" in the tags. I would also go as far to say not to mention that your first fic ever is your first fic ever because that could potentially turn people away from reading 😅 Obviously your mileage may vary here, but from personal experience and in my opinion, sometimes unearned and occasionally over-the-top confidence is much more bearable and compelling than constant self-deprecation.

6) Once again: write what you want to write. This time, though, I'm mostly talking in terms of when people think "I think this story is too OOC" "I think this story is rushed" "I'm afraid [some group of people] will give me hate for this fic."

Obviously, this whole point covers a variety of fics that people may not like or give a critical comment to; if it's something insensitive in some way, maybe that is an indication to think about it and do research on the insensitive aspect. Of course, I'm a big proponent of letting people learn and grow so even though I bring this up, I don't think people should worry about being insensitive with every little thing they write—rather, it's much healthier to accept that it can always be a possibility because none of us are perfect and we all grow up with internalizations. An opportunity to grow is an opportunity to better yourself as a person.

OTHER THAN THAT, for something like kink, or characterization, or unpopular dynamics, or a rare ship, or super minor detail accuracy (if you don't want to care about it, which I think is as fair as caring way too much about it lol), or, I don't know, angst... if you wanna write it, just roll with it! If people don't learn how to hit the backspace button, delete their comment, and don't let their words get you down. I also think these days the way "hate" is talked about is often blown out of proportion, at least for fic; more seasoned adults will not click on something that they're not interested in reading and being entertained by for ten minutes to several hours or so. If you write something weird and niche, it's more likely that you'll find people who ARE interested in it than otherwise.

Case in point: I wrote an 18k second-person POV experimental style death fic that has less than 70 kudos on AO3 but I've seen someone say that it's their favorite fic ever and another person left me like a 5 paragraph essay comment on it so I'm still really proud of it. Also, when I got into Super Junior fandom in 2009, my main ship was a "rare" ship—I literally scoured the entire internet to find/read all the fics for it and when there still weren't enough, I wrote so much fic for them that it inspired tons of other people to write for it. (Although it's still a pretty rare ship haha.) So if what you want to write is fulfilling for you in some way, it'll surely be fulfilling for someone else as well.

Good luck on your fanfiction adventures!!! If you have any other questions for me I'd be happy to answer them :) I hope this helps!