Ask HN: How do I become a great code reviewer?

How do yo review other people's code? What's the first thing you 'see' when you look at the diff? Does it change depending on the language? How do you manage the human aspect/personal dynamics of code reviews? Is there any good direct/indirect literature available on this topic?

I have been in the practice of building code collaboratively for about 10 years - admittedly not that long by HN standards, but enough to be exposed a spectrum of Code Reviews. Sometimes my experience was negative, but I have encountered a fair few sage reviewers who will make you happy that you put your code in front of them.

How do I better myself as a code reviewer?

I suspect it's equal parts technical _and_ emotional exercise.