The tradition of the button hole stems back to Greece where the button hole is worn over the heart to ward of evil spirits that can get in to the grooms heart and make him not love the bride anymore!!!
Men should wear their button hole facing up and on the left.
Women should always wear theirs on the right, however for button holes (i.e. a single or double flower and foliage) go flower up whereas tradition for corsages (lots of flowers usually smaller ones) point downwards. However I think it depends on the arrangement and how it is designed to be worn.
