For social meetings, you should shake hands with the other person. It is more common for a man to exchange kisses with women in social occasions than in business meetings. Males and females can hug women friends lightly.
Male friends can hug or embrace (the abrazo) each other or touch each other’s arms or kiss each other, depending on how good their friendship is. In Spain this is not a sign that one is gay.
Never touch, hug or back slap a Spaniard you do not know well, unless a friendly Spaniard touches you first.