Go for a straightforward but cool and relaxed option putting together a black puffer coat and black leggings. If you don't know how to finish off, a pair of black leather slip-on sneakers is a smart pick.
Black Leggings with Black Leather Slip-on Sneakers Casual Outfits In Their 30s
If you gravitate towards casual style, why not wear a white dress shirt with black leggings? Ramp up this outfit with a pair of black leather slip-on sneakers.