How do you do your blink animations?

[Geckos]

I've been thinking about this problem for awhile now.

The characters in my visual novel all have at least 3 poses with arm/head shifts for some of them. What do you think is the best way for me to tackle giving them blink animations?

Should I chop each pose up into different bits, so that all I am doing is swapping out the head of the sprite, and overlaying that head's unique blink animations? (i.e. head/expression angry, head/expression sad, head happy...)

Do I need to try to keep their expressions within 4 or so different eyebrow positions, so that each head/face doesn't need its own unique eyelid images?

Any thoughts or tips on the subject would be greatly appreciated.

[Endorphin]

I have everything on it's own "layer" in Ren'Py. =o
^ But this is not necessarily needed--I just prefer flexible stuff, like building the face while writing the script. (The coding is messier, of course.)
So all I need to do is to assign the blink animation to the eyes.
Having a separate eye layer in the composite image is probably going to be the easiest--and depended on the style it won't have anything to do wih the eyebrows, which can be nice as it's less work.

Sorry, I'm kinda tired. Just can't articulate myself today.

- En.