I agree with Kitty that lessons learned is a more useful term than best practices. However in my experience they too tend to be overly sanitized and consequently pretty useless. In particular, the lessons frequently leave out the part about what went wrong. I suspect that there are "corporate interests" at work in the release and publishing process that serve to strip out the reasons, to limit bad news, reduce liability, or avoid any appearance of incompetence.
We end up with lessons that sound like scripts from Lake Wobegon, where everyone is above average and mistakes are like fish stories of the one that got away.