I scoop out a bit of pigment, and mix it with a bit of loose powder in a small container (I use a clean lid of one of those cans of cake frosting usually). Then I swirl my 129 brush in the lid and apply as i would any blush. IME, adding the bit of powder makes it easier to blend the pigment on my face.
I dip my 224 brush into the pigment jar and just blend into my hightlight area, or you can use brush #187, or #109 for more then just a highlighting effect. Good Luck...
Definitely keep the plastic insert in the lid... Also, I use my pigments on my cheeks with my MAC 168 and I love it! Tan pigment on my cheeks is my fave blush of all time!