1. Even when I'm writing "bad guy" dialogue I still can't bring myself to use homophobic slurs. Like...I just can't type them. It's weird, because I think I wouldn't have trouble writing racist things, and I've had no problem having them use the word "retard"...but, for some reason I just can't bring myself to type that word that means cigarette in the UK. :P Which is really ridiculous, because I used to say it all the time myself when I was around 13 and didn't know any better.* Anyway, so, my bad guys are surprisingly tolerant assholes.
2. Every time I use the word "she", I think of my grandmother saying "Who's she, the cat's mother?" And then I want to replace it with the woman's name.
3. After reading and writing mostly stories involving only men, I tend to use full names rather than pronouns, even in scenes where there is only one boy and one girl. At least one of my readers finds it annoying, but I just can't stop. :P
4. Even though I'm a huge supporter of the evolution of language, now that I KNOW "alright" isn't a word, I have a really hard time spelling it that way...but, "all right" looks ridiculous to me...so I'm constantly using "okay" instead.
I'm sure there are more...but these are the main ones.
*I was never homophobic. I just didn't understand that joining my friends in using homophobic language wasn't helping society.