A grey wool waistcoat and a white turtleneck are an easy way to introduce extra class into your current styling rotation. When it comes to footwear, add beige suede chelsea boots to the equation. As the weather starts to warm up, it's time to shed those heavy winter layers and choose something lighter, like this look here. And if we're talking casual outfit ideas for 20-year-old guys, this combination looks good on almost any gent.