I cycle to work most days and wear cycling sandals. I leave the bike and sandals in a bike locker outside one of our buildings and walk barefoot to the locker room. After showering, I put on flip flops to walk to my desk and then kick those off. For a while I wasn't using flip flops, but one morning I got the evil eye from a higher up. Eventually I'll put on shoes and socks to go to meetings, the lab, etc.