I'm big on the concept of the right tool for the job at hand. Dash down to the store for something, whatever I've got on. (My pedals are reversable, so my footwear doesn't matter much) Long scenic ride with DH, cycling clothes.

I ride to work in what I'm wearing that day, with one pant leg pulled up (I'm a fashion plate, I'm tellin' ya) then change to baggy shorts & Tshirt for the ride home. I'd go more cycling specific, but I have the possibility of meeting patients on the way out, and would rather not frighten them.