I write and enjoy a pretty wide variety of genres, situations, and orientations. The one type of story I don't typically enjoy (or write) are stories where one partner in a sexual relationship is disciplining the other (for genuine discipline, not for fun) -- mostly that kind of dynamic just doesn't work for me (offends the "women's libber" in me, even if it's the man getting spanked). That said, I've been known to actually enjoy a few such stories, especially if they happen to include a good firm dose of a leather implement

And I've actually written a few as well (Colin and Mikayla, Whip Me for Being Unfaithful, and there's even one embedded in Training Amarra). But my forays into that dynamic are all kind of "special cases".
The other type of story that has a major squick factor for me is adults spanking children/teens and getting a sexual thrill out of it (or even just admiring their nakedness). I'm pretty sure I haven't ever gone there, nor am I likely to (unless it was like an 18yo "adult" with a teen partner close to their age).
As for schoolgirl canings, although I do like a good schoolgirl story, I was not at all interested in caning stories (or pictures, or videos) until I found my way here. Now I find that they are growing on me (which is maybe not so surprising given that I do like my spanking fiction harsh), and I'm actually writing one of my own at the moment (not especially harsh, for me anyhow). (I've no idea why, but the key scene in this story wrote itself in my mind with a cane, so we'll see how that turns out.

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Primarily, though, I write what I want to read, and I tend to enjoy my own stories when I go back to them (often when someone comments, and I want to refresh my memory).