You'll be surprised at how very easy it is for any guy to put together an off-duty outfit like this. Just a white long sleeve t-shirt and a crew-neck t-shirt. If you want to break out of the mold a little, complement this look with a pair of tan suede desert boots. You can bet this outfit will become your uniform when spring comes. Those who are curious how to sport modern casual looks as you drift through your 20s, you have your answer.