For a laid-back ensemble with a modern twist, you can easily rock a yellow long sleeve shirt and chinos. Go off the beaten path and break up your getup by slipping into a pair of black leather low top sneakers. Can you see how super easy it is to look seriously stylish and stay cozy when cooler weather hits, thanks to this look? When it comes to casualwear for 20-year-old men, this combination looks good on almost any man.