Man greeting Man - Men shake hands when greeting one another.  A firm handshake is the norm.  Good friends and family may engage in light hugs.

Woman greeting Woman - At a first meeting, women generally shake hands.  Many times a simple nod of acknowledgment will suffice.   Good friends may engage in hugs or exchange kisses on the cheek.

Man greeting Woman - At a first meeting a regular handshake will do. Many times a simple nod of acknowledgment will suffice.  Good friends may engage in hugs or exchange kisses on the cheek.