This might be contrary to what most people say, but it works for me.
I have to use a kabuki brush with MSFs because a skunk brush just disperses the pigment and I have no control over where it goes. A regular fluffy black blush brush results in an uneven, awkward application. I just dip the very tip of my kabuki, lightly, in my MSF and then buff it into my skin. It looks amazing and I can control where it goes because the brush is dense and doesn't "give" completely like a skunk––ridge of cheekbone, just the very tops of the apples of my cheeks, the tip of my nose, etc.