Two things One is a thin belaclava such as you can get from seirus, patagonia or from REI. The other is the nose, face wrap from seirus. A couple of tweeks to the neoprine and it fits great. This combination has allowed me to ski even when its -14f.
I would say that I've had success with the neoprene mask that jyarddog is describing. I went out in -20f which was -40f with the windchill for a good 5 or 6 hours and my feet were colder than my face. I didn't have any fogging problems either.