Its all about the weighting of the various parts.
Theres no way round it really as its just a lot of messing about untill you get a weighting that works, and then making a note of it for next time you use it.
The Gnomon ones probably the best, but it does vary on your lighting, get a nice look to the lighting with a standard lambert then switch to the SSS and adjust it to suit.
Thats really the best advice I can offer.
"No pressure, no diamonds" Thomas Carlyle