Director Lars von Trier made headlines on Wednesday as he, one might say, trolled the Cannes film festival by ranting about Hitler ("He is not what I would call a good guy, but yeah, I understand much about him and sympathise with him") and his ambition to make a porn film starring Kirsten Dunst and Charlotte Gainsbourg ("They want a really hardcore film this time, and I am doing my best"). As he seemed to lose his train of thought, Dunst seemed mortified and whispered to him: "Oh my God, this is terrible". Von Trier later apologised.

Whether Von Trier's comments were intentionally inflammatory or not, what is the best way to backtrack for a gigantic gaffe, or a very embarrassing faux-pas? What's your recipe for an apology that is honest, meaningful and will make one appear truly contrite? Can it ever be done?