My office falls into the smart-casual category between full on suits, and leggings/jeans.
I wear dresses or skirts 90% of the time I'd say, because I have a small waist, big bum and short legs, and I'm too lazy to find trousers that fit properly.
Some links:
Dresses:
Jersey dresses from me+em (like this or this) and Baukjen (like [[https://www.baukjen.com/uk/shop/baukjen/dresses/darton-dress-teal.htm
this]] or this). Would never pay full price, but wait for sales.
Tops:
Uniqlo for merino layering knits of various styles (also like Gap for crew necks but they do less colours). Woolovers cashmere merino mix is also good, and J Crew Tippis often go into the sale.
Long vests from H&M for underneath.
Also me+em again for layering tops if you like the "collar peeking out" look.
Silk shirts and tops from Uniqlo but I think this is a S/S thing for them as they don't have any at the moment - I can't recommend them enough.
Short sleeved knits from Jaeger also at half price in sale.
Finally if you don't mind polyester, Asos usually has some nice plain tops, I have this to wear over skinny trousers.
Skirts:
Can't really link as a good high waisted pencil skirt is my weakness and I own loads from all sorts of places, but J Crew do great structured ones (with code or in sale). The one I wear most is this ruched one from Baukjen, no doubt bought with a code!
Jackets:
I hate wearing jackets so never spend loads, I have ones from H&M, Topshop, Massimo Dutti and Mango.
There are very few shops I wouldn't buy from, but these are the things I've found to be my favourites for work.