This off-duty combination of a harrington jacket and white chinos is extremely easy to pull together in next to no time, helping you look amazing and ready for anything without spending a ton of time searching through your wardrobe. Unimpressed with this look? Invite a pair of black leather low top sneakers to switch things up. This combo is a pretty wonderful idea, especially for autumn, when the temperatures are dipping. This combination illustrates how to succeed in the smart casual fashion department as a 20-year-old man.