I agree with Gopldencup that T-shirts and skirts on women generally look smarter than Tshirts and shorts on men. This is because women's Tshirts are normally cut differently and do not look baggy.
In my office there is one male. We are not in the office much and are expected to wear smart clothes. During term-time I wear a suit if it is not too hot. If it is hot I wear smart, summer skirts and tops. My male colleague wears short-sleeved shirts and chino trousers but still smart.