Personally, I feel black trouser pants can be worn for formal & casual events. If you choose to go for a formal look pair it up with a nice white formal shirt  and heels or if you want to go for a laid back look then even a cropped top would work. I styled my black trouser pants with a blue collar top and paired it with a statement necklace & chunky boots. Also, I have an obsession with bangles & I’ve started pairing ’em up with almost every outfit of mine (lol, it may end soon or NOT!) 

Outfit Details:

Blue Collar Shirt: H&M

Boots: H&M

Statement Necklace & Ring: Aldo

Harem Pants: Thailand