Dark coloured jeans preferably (not totally black, just dark blue, grey, the likes), casual dress shirts with a t-shirt/long sleeved shirt (depending on the weather) underneath, a pair of sneakers and glasses (I need them, yes, but I wouldn't change them in for contacts or something, they make me look a lot better, so I include them here). Sometimes the the t-shirt is a nerdy one, sometimes it's not.
You can call it geek chic, I guess. I wonder how I look with a fedora, by the way, if it would compliment my favourite outfit or not, if it would even fit with me