In general i have a soft spot for shoes...so for guys the first thing i look at is usually their shoes. I hope that doesn't sound shallow but its honestly true - i think you can tell a lot about someone by what they're wearing on their feet, and the age/quality of the shoes (worn is a bit nicer than brand spanking new)
Vans, boatshoes nikes, all the stuff nsers like (see that shoe thread) immediately draw my attention, then i look at the rest of the clothes. Guys sporting crisp polos and designer jeans might be nice for some people but sure as hell not for me. Sweats or other chill pants or shorts and a tshirt are absolutely fine to be seen with in public. Evidently people look for different things in guys, and for first impressions clothing says a lot about you...it screams your style, mindset, etc even if you dont want it to.
Sparknootes: shoes say more than clothing for me