I am making my way through a book about warfare in the Napoleonic age and it cites that a common British tactic was to from up two ranks deep for increased fire power and fire off two volleys at close range followed immediately by a bayonet charge for shock value. Apparently it worked fairly well, I don't have the book with me otherwise I would quote soem specifics.

I tend to save bayonet charges until the enemy unit is about to break. If not I seem to take too many casualties in addition to having to worry about friendly fire.