Kids love face painting and a new face can provide hours of entertainment and imaginary games. I use Derivan face and body paint.
There are heaps of internet resources including video tutorials on Youtube that are really helpful.
G wanted to be a two faced baddy.
M always requests a rabbit face.
And of course the boy wants to be a scary freak. I think it worked!
My tip is to use a good quality non toxic face paint and to practice as often as the children let you.