Classical Greek Canon: Proportions based on certain body parts for the idealized human body. Generally had rounded, full oval faces.
Egyptian Canon: Artwork measured by hand size on a grid of generally 18 units.
Golden Mean: The golden ratio is used in portraits for the placement of features and various body parts in order to create harmony.
Vitruvian Man: The drawing of the man within the circle and square is based off of the “correlations of ideal human proportions with geometry”.