Summarize:

It is important to apply your blush in a well-lit location, otherwise you might underestimate how much you've applied. Natural light is best, however a well-lit bathroom or a lighted make-up mirror will do just fine. Your blush should only be applied after primer and foundation. The primer helps to neutralize any redness and will keep your make-up looking fresh for longer, while the foundation evens out skin tone, providing a flawless finish. Although traditional blush application involves applying blush only to the apples of the cheeks, this advice does not work for everyone. Instead, you should take the shape of your face into account when you apply blush:   Round faces: To slim a round face, apply blush to your cheekbones (which you can find by sucking your cheeks in like a fish) and blend outwards and upwards towards the temple.  Long faces: To soften a long face, apply blush slightly below the apples of your cheeks (the roundest parts) but don't extend the blush any further.  Heart-shaped faces: To balance heart-shaped faces, apply blush beneath the apples of the cheeks and taper off towards the hairline.  Square faces: To soften a square-shaped face, apply the blush straight across your cheeks, beginning about an inch away from either side of your nose.  Oval faces: Oval faces can get away with just applying blush on the apples of their cheeks, and blending well around the edges. To find the apples of your cheeks, just smile! The technique you use to apply your blush will vary according to the type of blush and application tool you're using.   Powder blush: To apply powder blush, lightly pound the brush into the powder, then tap the handle to remove any excess. Use a swirling motion to lightly apply the powder to your cheeks,  Cream blush: To apply cream blush, dab your flat-bottomed brush or fingers into the blush and lightly apply to the areas of your cheeks you wish to color. Then use a swirling motion to blend in the cream, working from the outside towards the center of your cheeks.  Liquid or gel: Use your fingers to apply two dots (no more) of the liquid or gel high on your cheek bones, then use your ring finger or a synthetic sponge to work the product into your cheeks using a dabbing motion. Most people are afraid of going overboard with their blush, so they tend to apply too little.  However, you want your blush to be somewhat obvious - it shouldn't just blend into your skin like foundation. Just keep in mind that it's easier to add more blush than it is to take it away. Therefore, you should apply your blush little by little, adding additional layers until the color is just a shade or two past what you think looks natural. If you accidentally apply too much, use a dry washcloth to buff away any excess color. To finish the look, get your hands on a translucent powder with a slight sheen.  Use a small brush to apply a little of the powder beneath the outer corners of your eyes, then use a swirling motion to blend it into the top edge of the blush. This will highlight your cheekbones and help the blush to appear more natural. Some people are confused about the difference between blush and bronzer and how each of them should be used.  Blush is used to add a pop of color and life to your cheeks, mimicking a natural blush, whereas bronzer is used to give a healthy, sun-kissed glow to the entire face. To apply bronzer, use a powder brush to sweep a light layer over all the areas of the face that the sun would naturally touch - the forehead, the cheeks, the chin and the bridge of the nose.
Choose a well-lit location. Apply your primer and foundation first. Apply blush to suit your face shape. Use the right technique. Know how much blush to apply. Finish with a layer of translucent powder. Understand the difference between blush and bronzer. Finished.