Rule #1: Do not avoid the difficult conversations. Your people will know, and you'll lose credibility in their eyes.
Rule #2: Everything you communicate can be done in a way that maintains or enhances a team member's self-esteem.
Rule #3: Own your feedback. Stop saying "we" think and start saying "I" think.
Rule #4: Ask for input.
Rule #5: Communicate what you know and what you don't know.