My favorite: raw egg. separate the egg white and the yolk. Take a fork and whisk the yolk for a few seconds, then dab it onto your face and let it dry. After 5-10 minutes take it off with warm water and a hand towel, then do the same with the yolk... It works wonders, no lie :)
Oh and used coffee grinds are a great exfoliant.
I've tried just about every homemade facial mask ever... And experimented on my own. These work, seriously.