When using their Hi Def Healthy FX foundation I would strongly reccomend using an appropriate primer from the same line underneath it. This will change the entire way that the foundation sits and goes onto the skin. I am sure you know the value of a good primer, but for a Smashbox foundation I think a Smashbox primer works best.
I've found that Smashbox foundations can be a little "goopy" but by having the matte finish of the primer on there first, it settles the foundation extremely well. It makes the foundation sit matte and gorgeous. I feel that this line of foundations really help the skin "glow" a lot more then others.
The foundations do look gorgeous when transposed through picture.
Good luck!