A denim shirt and a crew-neck t-shirt are a combination that every modern guy should have in his off-duty sartorial arsenal. Finishing with black leather casual boots is a surefire way to infuse a touch of class into this ensemble. Keep this ensemble in mind come warmer days, and rest assured, you'll save a lot of time getting ready on more than one morning. This pairing illustrates that in your late 20s your sartorial options are far from limited.