I don't have a tutorial, but setting keyframes for the displacement mesh with Liquify should do the trick...
Or, you could animate a mask.
What exactly have you tried?
I think the easiest way to do this would be to take your still into photoshop and make 2 additional versions using layers. Layer 1: eyes open, Layer 2: half blink, Layer 3: Eye shut.
Import the PSD as a comp and simply edit the layers. A blink is so quick that it should work just fine and it's just a lot easier in Photoshop when you're manipulating stills.
The other option, using some kind of distortion is much more complicated. You'll need to separate out the eyeball and the eyelid by masking a duplicating layers, then move the eyelid while the eye stays pretty much the same. You'll probably also need to move the mouth and cheek to make it convincing. It would basically be the same steps you'd use in a Photoshop tutorial. Duplicate layers, hold areas with a mask, and liquify.
Adding a wink to video is a bit more difficult and may need to involve some tracking, cloning, and other steps. It just depends on the shot.
I'll try your first suggestion, very un-savvy user not sure I know how to animate a mask, yet Thanks
Rick, thanks much for the Mona Lisa tutorial, should help a lot