You'll be surprised at how easy it is to get dressed like this. Just a charcoal suit worn with a navy crew-neck sweater. Brown leather derby shoes look amazing here. A great outfit to make you a well-dressed gentleman in his 20s, rather than just a gentleman in his 20s.
Navy Crew-neck Sweater with Charcoal Suit Outfits In Their 20s
This combo of a charcoal suit and a navy crew-neck sweater is an interesting balance between formal and casual. This outfit is probably what you've been looking for as a 20-year-old guy.