I am in the process of re-developing a work uniform; currently I am volunteering in a kindergarten classroom and try to model after the teacher in terms of clothing. Pretty much I've been going for skinny cropped black pants, either flat boots or pointy toe flats, and a fine-knit top or, today, a chambray shirt. I've also been playing with statement necklaces, which the kids seem to find interesting (although not as interesting as my volunteer badge ha!).

My work-wear is quite varied, but my fast fall-back formula tends to be skinny pants, a self-made tee, and a long cardigan, with booties, oxfords, or arty Mary Janes. In summer, I my fall-back is more likely to be cuffed chinos with self-made tee and shorter cardigan or denim jacket, and ballet flats, cutout booties, or sandals.
On days when I put more thought into what I'm wearing, I will wear harem pants or other flowy pant styles. They take more thought to get the proportions right, though, in my experience. Skirts are a struggle, but I do like to wear them when I can figure out how. Dresses are easy, but I'm self-conscious about baring my legs until we get about 1/2 to 3/4 of the way through summer and I just don't care anymore!

I love this thread and all the replies! I will be revisiting! I wish I could thumbs-up all the responses.

In the meantime I will weigh in that the important part of my uniform is predictability and structure (big boxy top or combination, over a more narrow bottom). It's a weird balance between being the authority (the "grown up") with also being entirely approachable by people at all levels, able to lug No Parking signs around when needed. (See Project Greenlight, Effie Brown for a reference. Or all our Denver YLF friends who work in museums or universities.)

Because I work in the film industry and most of the crew is in work gear including jeans, t-shirts or sweatshirts, and closed toe shoes, I dress the same, but with the intention of looking ever so slightly upscale and deliberate about the t-shirts and sweatshirts. If I'm at a meeting that's not on set, I can wear a denim pencil skirt and I can wear open toed sandals, but otherwise it's cropped pants or jeans. Even when I wear sandals, they have a lot of coverage; I love lots of beautiful leather in my shoes.

I see a dress in my Finds. It is totally a dream. I never would wear it.

No uniform for me, work is when I get to be most creative with my outfits and I try to take full advantage of that

Mois est chemise et cravate même en été

I have for the first tI've ever really tuned my uniform. I sometimes wear a dress with a blazer and flats or some kind of boot but generally I wear black skinny jeans or ponte pants, a knit top usually black or black with stripes and a blazer or leather jacket. I change my shoes but they are usually flats of some sort. I find it great not to have to think about it in the mornings now.