These are some of the practices we try to follow.
We deploy to production several times a day to reduce risk and get quick feedback.
This is enabled by a strong testing culture – if a commit passes our automated tests, it should be safe to go live.
We usually review commit-by-commit.
We default to working in pairs (and will sometimes do ensemble programming in a larger group). It can help focus, knowledge sharing, and reaching a synthesis better than we'd achieve alone.
But it's not dogma – sometimes nothing beats working solo. Pair programming is a tool we pick up when it makes sense and put down when it doesn't.
The important thing when something goes wrong is to figure out why it happened and how to all learn from that; not to assign blame.
Assigning personal blame, e.g. in the form of teasing or joking, is likely to make someone less likely to be forthcoming about their involvement in any future issues.