Lets see, feeling sexy and confident is something I've worked years to achieve. Something's I do is always make sure I wear cute panties. I love the cheekies from VS. Even if no one going to see them, it just makes me feel sexy. Another great thing to have to show of your amazing assets is to make sure your bra is fitted perfectly. Doesn't sound like you need a push up bra (lucky girl!) but a tiny lift is never a bad thing.
My only other tip is dress in what you feel comfortable in. Have your own style and go with it. Your not going to feel sexy wearing something that makes you uncomfortable. I feel my most sexy wearing right jeans and a fitted white t-shirt.
You'll get the hang of it soon!