Don't ever play the "girl" card. Don't play the "I'm a helpless victim who needs you" card. Be competent. Be respectful of others and they'll be respectful of you. Don't ever *demand* respect, take it. Do it because you love it, not because you want to prove girls can too.
Paying lip service to how much someone needs to recognize your achievements is a surefire way to be written off as someone who needs self-promotion because they don't have the chutzpah to allow their talents to speak for them.
Geeks almost never look at gender when they're being exclusionary, it's almost entirely a case of "can you talk the talk and not sound like an idiot".