If you really wanted to be sensitive you’d avoid binaries altogether, meme writer. (“Females” always makes me think of those “nice guys” who say “ladies” all the time. Brrr.)
I have between twenty and forty characters currently taking up brain space, not counting fandom/roleplay characters. It’s mostly men, since that’s my chosen genre, but writing women is a lot of fun, too. (They tend to be the voices of reason among the histrionic and dramatic boys.) I have not yet tried any characters who don’t conform to traditional definitions of gender, but never say never. There are a lot of things I haven’t tried yet.