This casual combination of a black turtleneck and a blue plaid long sleeve shirt is extremely easy to throw together without a second thought, helping you look stylish and prepared for anything without spending a ton of time rummaging through your wardrobe. And if you wish to immediately dial up this look with a pair of shoes, why not add a pair of brown leather casual boots to your ensemble? Rock this combination to assemble a more conservative look as a 30-year-old gent.