I rarely commute in my work clothes, for two basic reasons: I don't want to damage pants by getting the leg stuck in a chain or wearing out the seat, and dress/work shirts and long pants tend to trap a lot of body heat and sweat in the way that other gear doesn't. What I do most days is ride in shorts and T-shirt, then pull on my work shirt and swap on the long pants upon arrival. In the past I've carried a suit to work in a carefully folded garment bag strapped across my panniers. The exceptions are weather-related: my current commute is very short and mostly downhill, so if it's cold cold enough I can wear a work shirt under my winter jacket as a helpful extra layer and it doesn't make me sweat. And if it's cold and rainy, it's comfortable to keep my long pants on under my rain pants. For footwear I use clipless compatible sneakers that pass for ordinary tennis shoes and those are fine for walking around the workplace. In the rare instance I want dress shoes I'll just carry them in my panniers.