Choose a white long sleeve shirt and teal jeans if you wish to look neat and relaxed without exerting much effort. If you need to easily play down this outfit with a pair of shoes, opt for white and black athletic shoes. Come super hot sunny days you're looking for an outfit to keep you comfy and on-trend –– this ensemble is just what you need. This getup shows how to succeed in the casual style department as a 20-year-old.