My school's dress code requires formal attire, so a normal day at school for me would be khakis, dress shoes, and tucked-in button-down/polo shirt or a sweater. It sounds like a drag at first but I'm used to it by now so I barely even notice. On super-important dressup days, blue blazer + khakis + white dress shirt + navy tie.
Other than that, I'm generally in a t-shirt, sneakers, and jeans/shorts depending on the weather. For a night out though, it's pretty hard to go wrong with unbuttoned button-down shirt over a matching undershirt + jeans. :3