For an outfit that's super simple but can be smartened up or dressed down in a myriad of different ways, go for a suit and a white crew-neck t-shirt. Bring an extra touch of polish to this ensemble by rounding off with a pair of charcoal loafers. You can bet this combination will become your uniform come warmer weather. After thirty, you probably want to start dressing more like a mature gentleman. That's when ensembles like this are a tested option.