We all have different shaped faces and we can be catagorized into 5 types
Round: to thin the face. Apply the brighter blush to the apples of your cheeks, "but don't go in any closer to the nose than under your iris, or you'll get that Raggedy Ann look." Dust the contour shade below the cheekbone down to the chin line and blend.
Square: to soften the angles. Concentrate the brighter color at the apple, then brush it up and out to the temples to give your face a little lift. to round out your face, dust the contour shade from your chin to the middle of your ear along the underside of the cheekbone.
Heart: to soften the chin. Apply blush to the lower part of the apple. Instead of contouring, blend a liquid highlighter around the chin and along the jawbone. The highlighter will give your face more balance.
Long: to widen the face. Brush the brighter blush on the apple and extend toward the ear (not up the temple) to create the illusion of width. Dust the contour shade across the middle of the forehead (about a quarter of the way down form the hairline) and along your chin.
Oval: to get a natural look. For daytime, simply apply blush to the apple for a pretty, flushed look. At night, you'll want to heighten the drama. "For an extra pop of color, apply blush on the tip of the nose and across the bridge."
I have a long/oval face so I usually apply my blush to the apples of my cheeks.
Hope this helps you whatever shape you have!
Reference: Audrey Dao