Art of Giving

What's the ideal way to give tzedakah? Specifically, is it best to give whatever we can at any given time regardless of the amount, or should we postpone our tzedakah giving until such time as we can afford to make a more sizable contribution? Or is neither approach necessarily preferable to the other? The Art of Giving emphatically exclaims that, yes, it does indeed make a difference how we go about giving to tzedakah.