Square-Shaped Faces
Those with a square-shaped face benefit from blush applied directly to the apples of their cheeks, in a circular shape. This softens angular features by drawing attention to the roundest part of the face.
Diamond- Shaped Faces
If you have a diamond-shaped face, the goal is to a draw attention to the bottom half of your face. Apply blush along the top of your cheekbones, blending towards your ears to draw the eye down—and highlight your cheekbones!
Blush, like bangs, is a great way to break up a long face. Apply a horizontal swipe of color, which makes your face appear wider. You have two choices: apply from the apples of your cheeks to your ears, or start on the top of your cheekbones ad blend out to your temples.
Heart-Shaped Faces
If you have a heart-shaped face, apply blush along the bottom of your cheekbones, similar to the way you would apply contour. This will help balance a strong jawline by bringing the attention to your cheekbones.
Round Faces
Add definition to a round face by sucking in your cheeks and sweeping blush under your cheekbones. Avoid the apples, since that will make your face appear rounder.
Oval-Shaped Faces
If you have an oval face, concentrate your blush the top of your cheekbones, lightly blending up and back towards your ears. This will give your cheekbones serious definition.
Long Face
With a long face there’s more room for blush, so start under the pupils and blend to the middle of the cheeks. Make it a bit thicker, more of a slight semi circle or straight line, which will make your face appear shorter.
Source: byrdie.com