Summarize this article in one sentence.
A powder puff is a flat, puffy pad that comes in some powder compacts. It's usually palm-sized. To use, add a generous amount of powder to the puff. Dip it into the powder and don’t knock the excess off by tapping the puff against the lid. If you're buying your own powder puff, look for one that's about the size of your palm. Applying the powder lightly at first will prevent the puff from smudging your makeup. Tap the puff lightly all over your face. Then press more firmly after a light layer has been applied. If you’re applying powder under your eyes or around your nose, fold the puff in half. Then apply the powder as usual. A smaller puff gives you more control and prevents you from getting powder in places you don’t want it. Run the back of your hand against your face. If your cheek feels smooth and dry, you’ve applied just enough powder. If your face still feels wet or sticky, apply a bit more powder.

Summary:
Dip the puff into the powder. Apply the powder lightly at first. Fold the puff in half for small or narrow areas. Feel your cheek with the back of your hand to see if there’s enough powder.