I'm in the middle of lip syncing 600 frames of dialog:
This image shows my lip sync rig. Every character has a set of controls linked to morph channels applied to the various elements of the face. The eyebrows, eyes, and mouth are all separate meshes with different morph targets set to express a wide range of emotions and facial expressions.
Now, how you set up this rig is specific to 3D max, and better explained in a video tutorial, so I'll have to put that on the backburner list of things to do. A quick description of the controls:
Blink varies the shape of both eyes from wide shock or surprise, to fully closed.
Anger / Fear adjusts the angle of a taper modifier on both eyes to express anger or fear
This can be used in conjunction with the Eyebrow Anger / Fear control which adjusts the angle of the eyebrows.
EyebrowHmm ':| is used to lift one eyebrow, just like Spock in star trek.
The XY controller is set to control 4 morph channels of the mouth to express a wide variety of shapes
The Yell contoller is used to widen the mouth for shouting or emphasis
The Smile and Smirk controllers are used to control frowning, smiling, or smirking where only one corner of the mouth is intended to move.
I've refined and expanded this system as the film has progressed. Early versions only had the eye, anger/fear, and mouth XY controls. I've added on the other controls as I've needed to in order to express a wider range of performances out of my characters
The facial animation system I've developed is simple, but I think it works a lot better than trying to model and animate the actual geometry of a face due to the uncanny valley principle. Take a look at the facial animation attempts in most 3D animated films, like Final Fantasy or Skyland. It looks bad, because it take a lot of detailed subtle animation and movements to make it convincing. Due to the uncanny valley principle, my face models fall far enough out of the 'human normal' trap that a simplified animation can be applied without detracting from the overall experience.
Keep this in mind for your own films...