1. Be mindful of your/their partner. Put yourself in their shoes. If you think you would feel uncomfortable with the friendship, the chances are they will too. 
  2. Be inclusive. Don’t be secretive as that implies you have something to hide. Be open and invite your/their partner to meet each other.
  3. Too much communication could suggest unfinished business, keep contact from getting too frequent.
  4. Make sure that your partner always comes first, not your ex, and expect the same the other way round.
  5. Ensure that you are both on the same page and not wanting to rekindle the romance. If you are meet for a daytime coffee instead of an evening meal.