Why not wear a grey plaid blazer with black skinny jeans? As well as super functional, these pieces look nice matched together. You know how to tone it down: black chelsea boots.
Black Skinny Jeans with Black Chelsea Boots Casual Warm Weather Outfits In Their 30s
For a never-failing casual option, you can't go wrong with this combination of a white crew-neck sweater and black skinny jeans. The whole getup comes together quite nicely when you opt for a pair of black chelsea boots.