Hans-Paul Bürkner has 10 blue suits. The chief executive of Boston Consulting Group also shies away from striped shirts and unusual ties.

“Then I don’t have to make choices,” he says, over coffee in BCG’s London office. “If you have certain rituals about what to wear and what to put in your bag, it makes life easier. My choice of ties is not necessarily the best, but most of the people I work with wouldn’t notice.”