Even if you don't want to go as far as all black trousers and all white blouses, the idea of a uniform can make things very easy. For some people, that might be wife-legged trousers (in various neutrals, so gray, black, navy, tan, brown, etc.), sleeveless shells (solids and prints), and a cardigan. If you stick with a limited color pallete (so maybe grays, navy, blues, and greens), everything basically goes with everything else. The light blue cardi goes with the black pants and the blue and green shell. The gray pants work just as well, or you can wear them with a solid green shell and a Navy cardi. No matter how tempting that red cardigan is, or the orange and yellow shell, you don't buy them because while they work with some parts of your wardrobe, they don't work with *every* or even most part.
Someone else might wear skirts and blazers over blouses. Or wash and wear (jersey, ponte, etc.) dresses with cardis and blazers over them.
Regardless of the choice, having a uniform can really simplify things, but it doesn't have to mean you look identical each day. You know that when you grab any pant, any cardi, and any shell, they work. So there's no thought involved, and yet it doesn't look like you are wearing the same outfit every day.