A belted shirtdress is the ultimate no-brainer. Pair yours with slides for a look that can go from nine to five and beyond.
Take cues from Oliva Palermo and wear a patterned blouse under a patterned suit (make sure the scales of the patterns are different enough so the look won't make your cubicle neighbours dizzy). If you're feeling extra bold, add a snazzy embellished loafer.
You can get away with wearing a t-shirt at almost any office as long as you pair it with a crisp high-waisted trouser. Also key: tuck the shirt in.