Darren Rowse wrote some points to handle criticism for blogger, while I think it is very helpful for many cases. Noted here for me myself and also some of friends who like to discuss about critics. Its points:

1. Embrace criticism – "Not everyone will agree with you all of the time, but negative feedback is a sign that you’re making people think".
2. Consider the criticism – "Some criticisms are better than others".
3. Making use of criticism – "Take the emotion out of the criticism".
4. Take it on board – "Now’s the time to take the criticism on board—but not emotionally so much as practically".