Kadampa Life has 3 articles on the subject of how best to deal with criticism.
Extract: “We can overcome these limitations by understanding that criticism can in fact always be helpful if we shift our perspective as to what we actually need out of life. The mind-training adepts of old, Kadampas like Atisha and Geshe Potowa, famously relished any kind of criticism that came their way as a vital demolisher of their egos — they far preferred a good insult to being massaged by praise! Modern-day Kadampa teacher Geshe Kelsang explained to a friend of mine what he himself does when it comes to being criticized…”
Extract: “It is incredibly helpful to have help from holy beings when identifying and overcoming our faults. If we can mix our mind with theirs, we can look at ourselves from within that wide-open accepting and loving perspective. This is the best place to work on ourselves as it guarantees we will not identify with our faults and feel inadequate, unworthy or guilty. This only works if we are clear on the difference between our pure potential and the limited, faulty self we identify with when we have any delusions. Clearly we don’t want to end up hating ourselves; that would be entirely missing the point.”
Extract: “The emptiness of the self we normally see every day is what we are trying to meditate on and realize. Being criticized gives us an enjoyable challenge — the bigger or closer the target, “How dare they criticize ME!!”, the easier and more fun it is to knock it down, and the deeper the understanding of emptiness and resultant joy. We can therefore use specific difficult situations that cause this inherently existent self to appear strongly to deepen our understanding of its utter non-existence.