I'm a little new to actually writing, but I've wanted to do it for a long time, as I've got a very active imagination. I do still mostly lurk and read fetish fics, though.

My fics probably will seem a bit random in terms of what idea I go with. I can be a little spontaneous and pretty much the one thing that's likely to become a common theme is that my stories take a very realism-based approach and thus won't spare you the unpleasant realities, in particular that everypony has bodily functions and sexual urges.
Put another way, if you put a mare and a stallion in a box for 24 hours, at the very least they'll fart, pee, get very hungry, and consider getting physical, and the story should justify how that's handled.
As far as things like the laws of physics, I tend to write with a show-like setting and thus ponies are tough as nails, but they aren't coming back from a jump into a volcano.