There's an old saying that when packing for vacation, first lay out your clothing and money, then take half as much clothing and twice as much money. Similarly in options trading, after you get set up, de-install half the "analytics" packages and fund your margin account with twice as much money. This sounds silly or naiive, but if you trade options long enough, you'll reach a moment of enlightenment when you deeply understand this. Eventually the matter always hits the fan in a way that seems inexplicable based on your Greeks -- especially if you believed your were "neutral" this-or-that Greek -- and your only defense will be having plenty of dry powder on hand.