You can set keys on any of deformer’s keyable attributes (or channels). Keys can be set in the Channel Box, the Time Slider, the Graph Editor, the Dope Sheet, or by using the Maya Embedded Language (MEL™) commands.
When setting up characters, you can create attributes that drive deformer attributes by adding new attributes, and then defining relationships between the new attributes and the deformer attributes.
You can add new attributes from the Add Attribute window (Modify > Add Attribute).
You can define relationships between attributes with the
Connection Editor (Windows > General Editors > Connection Editor), the
Set Driven Key
window (Key > Set Driven Key > Set >
), or by writing expressions in the
Expression Editor
(Windows > Animation Editors > Expression Editor).