For some girls its a guy dressed in a certain style, but for me its a man who looks clean, put together, and has that vibe of confidence :)
Clothes that fit him well (no overly tight jeans or baggy I don't know "gangsta" pants or shirts haha)
No holes or stains ( it makes you look like you slept under a bridge lol )
Common sense of color/print combination ( striped shirts don't go with plaid! lol )
That's basically it for me whether your the type to wear a collared shirt, slacks, and a tie everyday or jeans, vans and a t-shirt, if you have confidence, match your colors, no holes, and it fits I'm going to notice you, and like it :) haha
Personally, I like indie style, especially on guys. Somewhat fashionable but still comfortable. As long as it doesn't look totally douchey (head-to-toe Ed Hardy wearer, I'm looking at you) and fits well I'm kind of "meh" on the topic.
i think a guy looks best dressed when wearing collared t-shirts and a belt so his pants don't sag.
They should NOT wear totally mismatching colors, weird hats, chains, skinny jeans, all black, tight fitting clothes, offensive or inappropriate clothes, or pants/shorts that are too short. or suspenders. or pink. or cowboy boots. or...you get the picture hahaha
basically simple polos and normal pants/shorts, all of which fit and are nicely kept and CLEAN.
Basics are clean and proper fitted clothes. Everyone has a different style and everyone pulls off different looks. As long as it's weather appropriate, situation appropriate and age appropriate, it's all good.
Oh man, this is a tough question! Style is an art. You are young so I think you are more into casual style, aren’t you? Well dressing is about hiding your body problems with style. If you have a great body everything will look good. Just avoid a wardrobe full of cheap crap, I would advise to invest into few pieces like jeans, polos, sweet, shirts and shoes of good quality... quality of your clothes is a guarantee of a sleek look. Also you can buy magazines for men, well yeah, it is a bit exaggerated, but once your eye is trained to see the essential ideas (i.e. to kind of overlook the 'eccentricity' of some looks) it really gives you basic notions of how to dress.
Clothes must always look fresh, be clean and smell good!