Tend to use the surname/family name if I am talking to a third party if the person in question is not well known to him/her. Usually use the first/Christian/given name if in face to face conversation. The boss still gets Mr.
Usually answer the phone with just my surname "S..... here"
Nick-names never use at work with employees only with friends, once got into big trouble with the union during an arbitration heaing when it came out that my nick-name for an employee was Johnny Ray , (he was a big cry-baby ), fortunatly for me the older panel members saw the humorous side
