I did a scorpion mask.
this is my costume:
this was what I was trying to make, Scorpion frm MK Trilogy (my fav game version):
I didnt really archive the sequence when i made it, coz i had quite little time to complete it. (besides, it was kinda messy...)
Anyway, the base was a sheet of 0.5mm Aluminium, to fit my face.
I used 2-part Epoxy Putty. It looks like clay, one white, and another brownish. Mix equal parts well, and slowly layer it over the already shapped mask. IT s can go unevenly, to speed things up. But the last layer should be smooth.
Tip- use wet fingers to smooth out parts. U can also dip ur fingers in water wen handling them; it sticks a lil. But if its too sticky, or too hard to mould;u got too much of either one component.
Lastly, spray it the colour it shold be (or u like)
I used elastic bands, fastened with hotglue.
And for any mask, esp those covering your mouths, make sure the inside, it resistant to water vapour. When condensed, it could wet the inside. If its pure paper / cardboard / mache (and the works), it could get quite bad.
In my case, the condensed water vapour actually slide off, and on to my suit (yeah...yucks). So i layered it with some sponge, just enuff to keep th vapour frm condensing directly on the cool alum surface.
it made it more confortable too...