There are two types of blush- the powdered blush and the cream blush.
Test the blush on your forearm to see how it looks like on your skin.
Once you know the right shade, select the right tone that would mesh well.
Take into account the color of your eyes and your hair. This would help you choose the right color and will make you look radiant.
If you have pale skin go for light shades and if you dark skin, go for deeper shades.
Go for shades like orange, cherry, purple and plum if you have darker skin tone. And if you fair complexion, go for colors like pink, violet, crimson and light browns.
You must know one thing; the blush should look natural because only then it will bring out the natural radiance.