Here I show a scrunch type shape I modeled to see how well this face I was sculpting for rigging was working.
Using the soft mod deformer was extremely helpful for blocking out the shape. We can change the falloff of region by holding down "b" then left clicking and moving left and right. We can change the center of influence by clicking on the key type symbol of soft mod. We can effect less region by using surface option instead of volume.
Face rigging book references:
Gary Faigin's "The Artist's complete guide to facial expression" pg 256 (scrunch type shape)
Eric Allen & Kelly Murdock's "Body Language Advanced 3D Character Rigging" chapters 11 & 12.