Stay calm and maintain a professional demeanor. Patience is key.
Avoid conflict, even when you know you are right. Give other editors the benefit of the doubt.
Assume good faith toward your collaborating editors, if not their edits. Assuming good faith is not intended to be self-destructive, but to avoid conflict.
Ignore attacks. Not easily done, but a real timesaver. Attacks and counter-attacks are hazardous to your mental health. The best and most frequently offered administrative advice is to move on, and, if absolutely necessary, return the next day.
Don't take it personally. Editors make mistakes. Communicating our thoughts is not easily done on the Internet.
Don't isolate your interpretation. There are many interpretations other than yours. What you read might NOT be what was meant.
Don't think of editing as a competition. WE are cohorts, collaborating to improve our thing.
Don't edit when angry or upset. Stay off the article and talk page in question. Never let your anger or frustration be the deciding factor in your behavior.
Don't forget the human dimension of Wikipedia editing. Keep things in perspective. There is a real, living and breathing, sensitive human on the other side of the discussion.