You're worried about ways to "counter the world". I say, good luck. I already screwed up on my daughter at 3, even while I was consciously and carefully trying not to.
Since she was little, I've been trying to treat her exactly the same as her brother. I vowed she would not become one of those girls who only thought about how they looked.
Around Christmas of 2012, I saw a red, Christmas dress at Costco, and bought it for her.
She had never had a fancy dress before, and she liked it enough. But the damage came when we went to the grocery store, and she wore the dress. Everybody praised how cute she looked. So many grandmothers and mothers in the store, stopped to tell her how much they liked her dress.
The constant positive feedback from strangers, in my opinion, had a huge impact on her. She liked the dress more and more, and we bought her more dresses. She also got more as gifts from relatives. Every time we go out, she's bombarded with compliments on how she looks.
We dress her brother (one year older) up in nice clothes as well, but strangers don't stop him to tell him how good he looks in them. There's something about girls, that makes people want to tell them how cute they look, and, in my opinion, it effects them.
Who doesn't like getting complimented? Who wouldn't want to do more of something that is generating so much praise from friends and strangers alike?
I've already lost the battle to have her grow up, not caring about how she looks. At 4, she cares deeply about it. Already, there is a difference in her world, vs her brothers world.
At this point, I've caved in and praise her dresses when she wants me to. You're only a kid once. It's nice when your Dad says you're pretty.
EDIT: In response to my commentors. I reject the premise that boys and girls are different, at least, prior to puberty. For a kid of 3 years, I contend that they are exactly the same, but that they are treated differently, and that is what makes the difference.