You see, You always say stuff like this , but I've never saw it. A lot of your avatars/signatures looked feminine to me. Though I really don't see how an avatar determines a person's gender in the first place.
Usually upon first meeting them, I assume their gender based on the one they list. While that method can be rather confusing at times since people do genderbend., I see it as the best way to determine gender until they state it themselves. If they don't list their gender, then I usually just used they or them unless they mention their gender. I also try not to assume gender based on their pictures or their avatars. Cause you got to remember transgendered people exist, people who are bigender exist, and people who are agender also exist, and I don't want to misgender someone out of carelessness cause they look male in a picture or have a "masculine" avatar.(And there's some people who get pretty annoyed by people who misgender them.)