Marrying a black turtleneck and black jeans will allow you to demonstrate your prowess in men's fashion even on dress-down days. Brown suede chelsea boots are an easy way to add a little kick to the ensemble. A no-brainer pairing proper for over-30 guys.
A black turtleneck and black chinos are the kind of a no-brainer off-duty look that you so awfully need when you have no extra time to spare. As for the shoes, follow a more classic route with brown suede chelsea boots. This combination illustrates that figuring out how to dress stylishly at 30 is quite manageable.