Author has written 9 stories for Doctor Who, StarTrek: The Original Series, Primeval, Psych, and Inside Out.
I am the mother of four children, aged 17, 11, 5, and 3. I run a restaurant in an 1860's era hotel in rural Wisconsin, and I dabble in fanfiction. I tend to like crossovers because of the opportunities they provide for illuminating different aspects of a character or setting. I frequently populate stories with original characters because the settings of some universes are characters in themselves, and I often like to get out and explore places where the main characters don't go. My currently published stories here are largely Doctor Who, though I have written in the Star Trek universe and am currently incubating some Steven Universe and Undertale, though not together. I have an inordinate fondness for telepaths. Really inordinate. It's rather embarrassing, really.
My personal moral hangups: I dislike when franchises write off an entire category of people, like ST does with genies and Who often does with cyborgs and mechanicals. Everybody gets a seat at the table. Everybody.
Da Rules (subject to change without notice):
I bend the canon, but try not to break it. (New stories or characters have to fit in plausible holes within the original work's timeline, which is why Alex's tenure occurs between the end of Martha's tenure and the start of Donna's.) Also, crossovers need to be in compatible universes...though any universe which acknowledges the Multiverse can crossover with all universes, because I said so.
Psychic abilities do not vanish just because it's convenient to the plot. Nor do they become ridiculously powerful just because it's convenient to the plot, mostly because then you're stuck with them later. If they did in the canon then you have to figure out why. (This is a reason why I have come to suspect that Leonard McCoy *might* be a latent telepath, empathic at least, in deep denial.)
TVTropes is my other favorite writing website. I could get lost in there for days.