What a lot of guys (NT, AS, doesn't matter) REFUSE to acknowledge is that your clothing is basically writing messages on yourself for other people to read. Your chosen style of fashion tells a short story - a summary - of who you are and what you're like.
Each item of clothing will represent just a few words - a nice shirt on a guy could say he's clean, well-groomed, intelligent, modern and strong. The tie he puts with it could say he's got a bright, effervescent personality and a strong sense of humour because of its colours...or alternatively a more traditional tie could say he's very formal, serious.
The whole outfit is important too. My guy wears old shorts and has an unending supply of t-shirts. He's always got a cap on. He's 17 and has quite a grown-up, mature face...the childish dress sense not only blatantly reveals his immature side, but the fact that it clashes with his features age-wise and the fact that it's so CASUAL also says he doesn't care about his appearance. To the point he doesn't mind embarrassing me with it Trust me lads. Most girls don't want to go out with someone that's pitifully dressed.
This isn't to say that you MUST comply with the exact current trend. That would be letting someone write THEIR message on you! With so much on offer out there, and with what's already in your wardrobes, you're 100% bound to find your own style.
Just remember what different things say though. Socks with sandals may be darn comfortable but so's finally ridding yourself of an itch with a public emergency crotch rearrangement
One thing I can say for the ladies...watch the waistlines on your clothes! Pants that sit on the hips are more flattering, but also are more modern. High-waisted pants and belts make the hips look larger and the waist look smaller, but it makes your torso look very short. And to execute this style without looking very old-fashioned it really should be done with a professional, high fashion approach. Not with jeans.
So yeah - keep that in mind. Clothes aren't simply to protect you from the elements and to be comfortable now, society has mutated it into 'fashion' - a way to speak to people. Each item speaks a few words. Write your message carefully if you want people to react to you in a certain way - if you don't care, who KNOWS what you're saying to people!