One of the important things we figured out was to always keep in mind perspective and which section of the jaw/mouth/piece was facing us. To that end, there were several times where we propped up the upper jaw (U) on top of the lower (L) so we could have a general idea of the final picture.
This is (U) before we started paper mache of the underside, but with the teeth stuck in--we stuck them through the chickenwire, then duct taped them in place, trying to make sure they were semi-snaggle toothed.
Still to do: spray painting the mouth red, painting the tongue...and assembly. But coming along nicely:)
**UPDATE** Apparently I am susceptible to demon possession. Nothing else really explains why my body sat itself up from the comfy chair I had collapsed in and walked itself back out to the garage to work on the interiors. It was actually fairly non-traumatic, only took another hour or so. I first made these white tubes to put around the teeth to make sure that the red paint didn't get on them--they worked out awesome. They allowed me to get close to the gums without worrying about painting the teeth or getting flecks of red on them.
Doing the second jaw:
Towards the back of the throat, because I was running low on the red, I took some brown gloss and did some spots of brown on top of a light layer of red. Then took a crumpled up newspaper and patted it a bit to give it some texture. Turned out fairly well. I then took the brown and, aiming from the back to the front, lightly sprayed a mist of brown, just to give it a little depth. Probably not going to be visible in the night, but it looks mildly more artistic.
And finished, without the tubes: