My solution to the problem comes in two parts. First, pick pieces that shout officewear in structure. Don't run from the actual pieces of clothing you are expected to wear. Embrace the blazer-and-pencil skirt combo, because you'll never feel out of place, as long as you find a fit that you are comfortable with. There's security in that. Second, find freedom in colours and textures, and avoid anything too matchy-matchy like the plague. Mix and match like there's no tomorrow. I guarantee it: you'll always look office appropriate, but never boring.
I team my floral brocade blazer with a black velvet pencil skirt and a subtle print blouse. The combination is unexpected, super feminine and colourful, but - and this is the best part - it's totally office appropriate. People in the break room might go for a second take on what you're wearing, but no one will tell you it's not suitable for work.
For the days when I feel like wearing something a little tougher, my go-to blazer-and-skirt outfit includes a slim-cut men's shirt, a black boxy blazer and a brown suede skirt. The texture of the skirt breaks the mold of traditional officewear subtly but powerfully. The whole ensemble is a somewhat trendy mix of menswear and womenswear, and again, it's completely office appropriate. The look changes entirely depending on my choice of footwear, too.
All the clothes are second hand.