Pairing a black crew-neck t-shirt with charcoal skinny jeans is a savvy choice for a laid-back and cool outfit. Bring a more elegant twist to an otherwise mostly dressed-down look by finishing with beige suede chelsea boots. This getup isn't a hard one to score and it's season-appropriate, which is important when it's super hot outside. This combo shows how 20-year-old gentlemen succeed in the style department.