A black crew-neck t-shirt and charcoal skinny jeans are a perfect pairing to sport on dress-down days. Black and white athletic shoes work spectacularly well with this ensemble. This combination illustrates that in your twenties your sartorial options are pretty much limitless.
You'll be surprised at how very easy it is for any guy to pull together a laid-back outfit like this. Just a black crew-neck t-shirt and black cargo pants. Dial down this ensemble by slipping into a pair of black and white athletic shoes. Now that's how you keep it casual in the fashion department in your late 20s.