Mine kind of goes all over the place. But mostly it tends to be "coming of age". And no, that does not always involve young characters, but can also mean people who go through a major change in their life and finally "grow up". The 25 year old slacker that finally gets a purpose in life for example.
I have written long romantic stories. I have written short stories about streetwalkers in LA. I have written several that are superhero stories. And quite a few that I call "Dark Tales" that are often rather dark, but have twists at the end (akin to Twilight Zone). And more recently, I have started to take on period pieces. I have covered the 1990's, 1980's, 1960's, 1950's, and now the 1940's like that. Mostly single short stories, but where I try to immerse the reader completely into that decade I am writing about. Everything from the music (big band), the clothing (bullet bras), and TV shows and movies.
I have done space sci-fi with robots, fanfic, chemical sex change, even one anthology series where the title and part of the plot comes from a song (so far only 2, The Who and Tom Lehrer). One based only on a title as part of a challenge, even a semi-horror where it was an "outside looking in" on a character reliving a "Groundhog Day" life, and their interaction with somebody else.
Mostly, I just go wherever my muse leads me. I often joke I have little actual input on where my stories go. I just put onto paper whatever my muse whispers into my ear. And sometimes to be honest even that surprises or shocks me in the end.
Myself, I never really worry about being "popular". I write for myself, although I am glad if there are others that appreciate what I put down in phosphors on my screen.
Plus, readers can be rather fickle. I have had stories I thought were really good turn out to be "Meh" to the readers. Then again I have also had stories I was not all that impressed with even when I wrote them that were surprisingly popular. But if there is one thing I learned, it is that multiple-chapter stories posted one after the other tend to attract more readers over time. I can only guess that they might miss it, but if they see chapter after chapter posted, many will eventually take a look just to see what it is about.
I tend to resolve it one of two ways.
First, is to take a break and work on something else real quick. I have been working on one story for almost 3 years now, but I have tossed out over a dozen short stories in that time as well. Mostly when I felt the story was getting to "cute", and I wanted to write something darker. So I would toss one out, then resume writing.
If it is more serious, what I actually do is restart the entire chapter I am stuck on. Quite often, at least to me it seems to happen when somewhere inside I know it is not working, so I simply restart that chapter and try again. 9 times out of 10 that then clears it up. I have quite a few chapters with (old version) appended at the end, those are where I had to do a restart. And I may revisit it and try to incorporate it at a later time.
Another thing I often do is include what is or could be an "unhappy ending". And I actually do this for "balance".
Most times I tend towards long, romance type stories. And on more than once occasion, I have found myself starting to get a "sugar overload" from all the sweetness. And generally when that starts to happen, I write one or two darker stories. Nothing really like snuff, torture or anything like that. But it may have the end of a relationship, or something else tragic. I find writing something like that helps me get it out of my system, so I can return to the light and fluffy style again.
I have had it happen to me more than once. Even have had to have some stolen works removed from Amazon.
By and large, I do not care, so long as they are not making money from it. I always gave my writings away for free, and from my earliest days on ASSTR I only asked that they not be placed behind pay walls. I even had some conversations with Ann Douglas about that, and like me she long ago gave up trying to fight the thieves. I am the same, but still go after any that tries to actually make money selling my works.
More than a few know about it.
I have let a few members of my family and close friends even read my stuff. And several years ago when I found out somebody had stolen one of my works and was selling it on Amazon, I put out quite a tirade on FB about it. And of course more than a few asked me exactly what I had written, and wanted to read it themselves.
With me, most times it has been a short single chapter story, in which something about it just demands I come back and write more. And it may be the setting, or the characters. But 2 of my longest stories started exactly that way. Intended on being only a single shot, but I just could not stop writing.