3/4 length trousers - fashion advice?

Ive just bought a pair of black plain 3/4 length trousers for work. what should i wear with them? i work in an office, but i am not client-facings so i dont have to be ultra smart. flats or heels? and what style top? thanks!
Answer
I wear my black 3/4 lengths with either black ballet stylee shoes or some strappy heels if i am having a nice hair day :-p i also work in an office and either will look nicex