There are three key things to remember about the jaw:
1. The jaw is the slowest-moving part of the mouth when talking:
Sudden, sharp movements can feel unnatural. If these exist in your vub then use Jaw - Open keyframes to smooth out these movements.
2. The jaw is the biggest contributor to the viewer’s perception of performance size.
Reduce or increase the size of jaw movements using the Best Practices guide for keyframing.
3. As a general rule, the jaw movement in the Driving Data is moving in the right direction on any given frame, so it’s important that placement of keyframe overrides is not damaging this by introducing unwanted changes of direction.
