Two-Handed 'C' shape
M: Shape your right extended index finger and thumb into a 'C' shape.
H: Place your two handed 'C' shape hand under the person's hand.
C: Shape the person's Index finger and thumb into a 'C' shape.
B: Trace your index finger down the person's thumb then up their index finger.
One-Handed 'C' shape
M: Place your whole hand into a 'C' shape.
H: Place your hand under the person's hand then place your whole hand into a 'C' shape.