Why not try pairing a grey crew-neck sweater with leggings? Both of these items are very comfortable and will look wonderful when paired together. As for the shoes, you could take a classier route with a pair of black leather ankle boots.
Grey Crew-neck Sweater with Leggings Warm Weather Outfits In Their 20s
For something more on the casually cool end, wear this combo of a grey crew-neck sweater and leggings. With shoes, go down a more elegant route with black leather ankle boots.
Go for a grey crew-neck sweater and leggings for a laid-back twist on day-to-day style.