The sign for hippie uses a "bent-4" handshape. The fingers can be thought of as representing the "long hair" worn by hippies.
Aim the "hair" a bit back and then "swing" it forward. Do this movement twice as if showing how a hippie's hair might swing back and forth.
HIPPIE:
Animated: "Hippie"
Notes:
It is also common to see this sign done with two hands. (One hand to each side of the head.)
Notes: