Personal Preferences mostly…
I see people use Mix mode and get good results as well as add…but in this case, with the MN-Mask I get the best blend with Overlay…Mix just cancels out the effect so that it can only be seen in Hard Light and extreme angles… Add makes those areas that need less intensity via the mask a bit too harsh, in the shadowed areas…
OVERLAY…
MIX
ADD
I have also seen people using math nodes in various ways, and that I just don’t like at all… 