One of Rabbi Joseph Telushkin’s preoccupations is to make his reader aware of the constructive or destructive power of words. Most of his ideas on the subject can be found in his book Words that Hurt, Words that Heal: How to Choose Words Wisely and Well. However his ideas are also developped in his other works.
I have just reread some advice that seems very sound. Thus Rabbi Teleshkin suggests that if you are angry with someone and want to voice your anger, you should concentrate on the person’s actions, not his/her personality.
Therefore you should be careful not to use words such as “always” (you are always messing up everything you do) and “never” (you never care about anyone except yourself). Such words will demoralize the person you are talking too.
In my opinion if you make such definitive statements, your message will be lost as the person won’t recognize himself/herself in the portrait you draw.
Rabbi Telushkin suggests that to be more efficient when expressing discontent you shoud “restrict you anger to the incident that provoked it”.