Who said you can't make a fashionable statement with an off-duty ensemble? You can do that easily in a dark green puffer coat and a turtleneck. Avoid looking too casual by finishing off with a pair of black leather derby shoes. A perfect pairing to show your maturity even as a man in his 20s.
A dark green puffer coat and a turtleneck matched together are a sartorial dream for men who love cool and relaxed combos. White athletic shoes will add more character to an otherwise mostly classic ensemble. Overall, an ideal example of off-duty fashion for 20-something men.
For an outfit that's very easy but can be modified in a myriad of different ways, consider teaming a dark green puffer coat with a turtleneck. Introduce black leather casual boots to the mix et voila, your ensemble is complete. An ensemble completely worthy of a 20-something's smart casual wardrobe.