For an ensemble that's super simple but can be styled in a ton of different ways, dress in a blazer and a blue crew-neck sweater. More sophisticated ensembles like this look well on young guys.
Blue Crew-neck Sweater with Blazer Smart Casual Outfits For Men In Their 20s
Dress in a blazer and a blue crew-neck sweater for dapper style with a contemporary spin. For footwear, you could stick to the classic route with a pair of tobacco leather monks. Overall, a great choice if we're talking outfit ideas for young men.