Meh... I usually just get into the character's head and play them that way. The gender of the character just usually doesn't factor in that much. I know I don't use stereotypes (or I hope I don't), but I also don't try to 'act' like a girl either... Then again, when I'm playing a guy, I don't act like a guy either.
Mostly, it comes down to how I picture the character and how they'd react to certain situations. When developing a character, I establish a "Logic Path" for that character and sometimes the gender affects that, sometimes it doesn't. I'm really just in it to tell their version of the story. *shrug*
My groups also didn't harp too much on the calling me "her" while playing, unless it was in character. And I guess I played her well enough that slip-ups like that were rare.
