For a laid-back getup, marry a crew-neck sweater with grey chinos — these two pieces go perfectly well together. You can get a bit experimental in the shoe department and spruce up your outfit by rocking navy loafers. That's the look for a man in his twenties to portray you've got what it takes to go places.
For a casual ensemble, dress in a crew-neck sweater and brown chinos — these items play really well together. Give a more elegant twist to an otherwise standard ensemble by slipping into navy loafers. This combination should erase any doubts you had about dressing elegantly as a 20-year-old guy.