You have to dress for the occasion. Think about who your "target audience" is, and plan accordingly. A lot of people think that dressing "nice" EVERYWHERE you go will make people think you're sophisticated or something.
I was at a college party recently, when these three older guys, probably in their late twenties, showed up, dressed to the nines. Everyone stopped what they were doing, and stared at them as they stood in the hallway, going off on some spiel about how they were alumni or something. Needless to say, everyone was creeped out, and the well-dressed trio went home empty-handed.
I was wearing a Hurley shirt with some jeans and a pair of Vans, and I did pretty good that night.
