The secret to dressing to impress?
Make sure you're the one who's impressed!
Everyone has their own taste in clothes and style.
Some like it bright,
Some like it dark,
Some like it short,
Some just weird (hey, who am I to judge),
you get the idea.
My point is, if you want to impress someone else, stop second guessing youself wondering what they like or might find attractive. Put on something that makes you wink at yourself in the mirror and say " OH YEAH!" and most likely, anyone else near you would be thinking/saying just that!!
If you are wearing something that makes you feel good then naturally you are going to look great too! Remember, its so much sexier to watch a girl who's having fun that then girl who can't move because her feet hurt or her panties will show!!
So go ahead. IMPRESS YOURSELF and the world will follow suit. :)