This combo of a dark green crew-neck sweater and skinny jeans is undeniable proof that a straightforward casual look can still be really interesting. Not sure how to complement this getup? Rock a pair of burgundy leather brogue boots to ramp it up a notch. This combo is a nice pick when it comes to a cool look that transitions easily into fall. Think it's hard for 20-something men to master smart casual dressing? This combination is a clear demonstration of otherwise.