I was thinking about this too today April. I'm allowed to wear jeans since I'm an intern (actually a volunteer...long story...). But I want to make a better impression so I'm trying to dress more like the staff, who only wears jeans on Fridays (and I don't work on Fridays).
The part that perplexes me is the fact that even though jeans are not allowed (presumably due to the outdated idea that they are casual), everyone still dresses REALLY casually anyway. Polo shirts and corduroys don't cut it for me, personally. I think jeans and a sweet blazer looks MUCH sharper. But it's not up to me, I suppose.
Like Ana, I'm mostly gravitating towards skirts and dresses. Not even "fancy" or professional dresses since, as I said, the rest of the staff isn't exactly dressy...but nicer and dressier than a lot of the other gals in the office. Today I wore my purple geo print mod dress with black cascarding cardi, black sheer hose, black boots, white watch, and citron necklace (bless Angie for donating the last two items).
If I were working 5 days a week, I would need to do some serious shopping as I don't have enough biz casual stuff. I wonder if dressed up leggings are okay? I feel like they are on YLF but probably not "the real world" (stupid real world).
I'll also wear my MC pants, but somehow I just don't feel as fab in pants. I just feel frumpy and old. I think a lot of that is because I don't usually wear heels. I'm going to take my MC's to the tailor to let out the hems for the few heels I do have and I think I'll feel better in them.
Also, I know this isn't totally relevant since we were talking about bottoms, but I love waistcoats!
Can you wear a dark denim skirt? I think I could get away with it where I am. Not sure if it's the same with you.