Got these from this article in Psychology Today

• Always lead with questions: How do you think you’re doing? It gives the recipient joint ownership of the problem and helps him feel included, not excluded.
• Never give criticism unless it’s been invited; unsolicited negative feedback only provokes annoyance and will be discounted.
• Make sure you are seen as having the authority to give corrective feedback. Criticism from those perceived as peers or unqualified to give it incites resistance and rebellion.
• Distinguish whether a demand for change reflects your needs or is a valid critique of how someone is doing something. Know when “You’re too demanding” really means “I wish I felt more accepted.”
• Never give feedback when you’re angry; anger alienates the listener. Expressing disappointment is more productive.
• Know who you’re talking to. Narcissists take any criticism as a personal attack; the insecure lose all self-esteem.
• Know yourself, too. If you’re relatively insensitive to criticism, curb the tendency to be heavy-handed when delivering it, says Cacioppo, who counts himself among the less sensitive.
• Expect defensiveness as a first response to criticism; a change in performance may come later.