Dating small girls, ie. Asians, Pigmies, or even Dwarves, will in some cases elicit amazement from your target girl. While following the rule of the smaller the better is usually a good rule of thumb, there are limits: see warning below.
As a warning: I recently learned about the smallest girl in the world, who lives in India or somewhere, and is only a foot or so tall. Obviously, this sort of size difference is criminal and downright impossible, logistically. Don’t be a prick about this.