Protecting the good hours

Work out when your good hours actually are — most people know, and most people spend them on email anyway. Then defend a block of them with something structural: a time nobody can book, a particular room, a device that cannot do the distracting thing.

Put shallow work deliberately into the bad hours, where it belongs and where it does no harm. Admin done indifferently at four in the afternoon is still admin done. Hard thinking attempted at four in the afternoon is usually nothing at all.