I keep seeing posts around I wish there was more femslash/rare pair/this particular thing.
You know the way to get that? Comment on what’s already there. You want more of those two awesome ladies who would just have the hottest sex ever? Rave at the authors writing that! Want more of those two guys who were in one episode but different episodes? If there’s something already written, go and comment on it! What about that particular kink that just gets your engines going Every. Damn. Time. There’s already some written? Have you let the authors know you loved it?
The way to get the fic that you want, is to appreciate what there already is. For authors who dabble in things that aren’t the fandom OTPs, the radio silence can be enough to stop you trying that again.