Well that's... difficult.
I guess one thing I feel okay with in terms of my writing, aside from the porn is that I think I do okay in terms of realistic dialogue for the characters. One of the things I can't stand in terms of the fandoms I write for is the manner in which characters speak, and I don't mean necessarily in terms of them being OOC. You can have a character be perfectly in character, but if the flow of their dialogue feels forced or stilted it can totally throw me off, so I try (and I think I succeed!) to make my dialogue feel right for the character as well as the mood and what emotions they might be having, ulterior motives, etc.
Thanks for asking!