I have a stand up plastic file holder on my desk, quite small, but it holds six stiff plastic clear files in it.  I have marked each one Monday, Tuesday, Wednesday, Thursday, Friday, and one for Next week.

Each day I file agendas, minutes, notes etc., relating to each day of that week, and other ‘stuff (similar) for the next week.  The day before say Tuesday, late afternoon on the Monday, I print off my boss’s diary, and then attach the documentation that he might require for say a meeting the next day.  That way, he has his daily diary plus all necessary documentation attached for it for that day.  No lost agendas, appointments etc.

Very handy, and extremely cost effective.