Young Rebel is a must have expression pack for Teen Kaylee 8 and Genesis 8 Female(s), that consists in expressions organized in three folders (Full Face, Upper Face, and Lower Face), and you also have pose control ERC dials to apply each full face expression. So you can add expressiveness in three ways:
USING FULL AND PARTIAL EXPRESSIONS: Using the partial expressions, you can move all the face, or just the upper and lower parts of the face, mixing both as you like, creating your own original expression for your renders.
USING POSE CONTROL DIALS: Using the pose control dials, you can apply a full face expression as much as you like, and also mix it with another expression dial. It is great to create transitions between expressions in animations or series of renders.
USING BOTH: In many cases you can also mix the partial expressions with the dials.