So true! Whenever I have something important at work, I always wear heels and a dress. Not because I want the men in the room to drool at my legs, but because I genuinely feel more confident and better able to give a presentation when I'm wearing heels. It actually improves my presentation.
But it's not always heels and make-up. I guess it's making your looks match your acts that makes you more comfortable. Wearing heels in an outdoor gear store makes me very self conscious sometimes, as if wearing heels makes me unfit to go for a hike or camp in a tent. And whenever I walk into a DIY-store I want to wear my filthiest pants all covered in dust and paint and wear gloves. I don't want the people there to think I'm just a cute girly girl shopping for her boyfriend who doesn't know what she's doing - I want them to think I know exactly what I'm doing. And it actually works!
I know!! it's an amazing "trick", isn't it? I agree it's not just high heels and all that pretty lady shazam. I hate being the pretty clueless girl when it comes to it also :)
See, to me this is a fantastic little tool - you're making yourself think you know what you're doing by making others think that. This isn't a question of whether you know or not, but often, we know what we're doing, but lack the confidence to show it and that digs into our ability.