For something more on the casually cool end, opt for this combination of a black knit cardigan and a black crew-neck t-shirt.
Black Crew-neck T-shirt with Black Knit Cardigan Outfits For Women In Their 20s
This laid-back pairing of a black knit cardigan and a black crew-neck t-shirt is capable of taking on different nuances according to how it's styled. Rounding off with black suede heeled sandals is an easy way to bring some extra zing to your look.