This casual combination of a long sleeve shirt and black jeans is a never-failing option when you need to look neat and relaxed but have zero time. You could perhaps get a little creative when it comes to footwear and smarten up this outfit by finishing off with a pair of black derby shoes. While dressing for wintertime can be a bit daunting, outfits like this one make you feel excited. So as you can see this getup is something you can totally wear as a 20-year-old.