The most thorough form of code review is probably tag team comments. I have only achieved this level of collaboration once in my career. Tag team comments are simple; have someone else comment your code while you add comments to theirs. This has many of the benefits of extreme programming without having to share a keyboard.
Adding comments to someone else’s code forces you to really understand what they are doing rather than just giving the code a cursory glance. It also leads to much better code comments. Tag team comments might be a little too extreme for you, but you should always encourage other people to add comments to your code when they are reading through it or fixing bugs.