If you're just out for the day then anything goes from shorts, T-shirts, tank tops for girls, bikini wear, etc. If you are asked to a casual party then shorts are still in (bring along a bathing suit just in case) and anything you want to wear. A person that is confident won't be afraid to be a little different. If it's a fancy party then dress in the appropriate clothing required. Don't wear shorts when your date is in a cocktail dress. The best way to understand what fashion is in or out is to 'people watch.' Some people go around in spandex and I often wonder why they aren't like one large elastic band and could go flying out of it at any given moment. I still watch for that one! LOL Other people wear the longer shorts (guys) and a sloppy shirt or T-shirt, some wear hoodies and baggy pants. When in California my eyes were wide open when I saw an array of circus performers going to work. Anything from a skimpy cocktail uniforms, bright frilly clothes (had to wear my sunglasses LOL) to different styles. Different styles (within reason) is what makes a person unique. If I see a person dress quite differently (Bohemian) then it makes me want to get to know them more. Brings the wild child out in me. If you simply don't know what to wear ask a friend who is into the latest clothing and go clothes shopping. I often ask my niece or other young people I know what is in or out. I'm a lot older, but don't feel (within reason) I have to dress in granny clothes, yet I'm classy about it and don't try to look 20 years old again.