1. Don't make assumptions about the situation or the other person's perceptions, motivations, or reactions. You'll get a much clearer and more accurate picture by asking the other person directly.
2. Don't take it personally - it rarely is!
3. Don't look for blame. Instead, try to identify cause.
4. Don't avoid the problem. It'll only get worse, breed resentment, and resurface at a later date. You've simply got to deal directly with the issue at hand.
5. Don't attack the other person's character. That's just playing dirty. It will not help you work things out and it will almost certainly have a lasting, negative impact.
6. Don't gossip about the problem or about the other person involved. It's unprofessional and will only make matters worse.
7. Don't bring it up in public. This is a private matter to be resolved between you and the other party.
8. Don't bring it up when there's not enough time to address it. Instead, leave adequate time for a thorough discussion - or introduce the issue and schedule a time to resume talks in the immediate future.
9. Don't bring it up when you're angry, stressed, or feeling ill.That's a disservice to you and the other person involved. Wait until you're calm.
10. Don't address the situation in an email. Email leaves far too much room for misinterpretation. While we're on the subject, don't copy others on a personal matter. This will almost certainly make the other party feel defensive, angry, or humiliated. It won't, however, help resolve the problem.