How do you prime your face before putting on L.A. mineral make up? Or any mineral makeup brand?

What exactly do you do to ';prime your face'; before putting on any of the make up?How do you prime your face before putting on L.A. mineral make up? Or any mineral makeup brand?
I use Bare Escentials mineral make up. They have a product called bareVitamins ';Prime Time'; foundation primer.





It works really great! It's a little pricey but a little goes a long way. 1 fl oz bottle has lasted me 4 months so far and isn't nearly done.