Agreed so much about log messages. I have a personal rule about them. You know how when you fix a bug it's good practice to add a regression test alongside the bugfix, so it's harder to introduce again? My rule for logs is that if I had to debug something and the logs did not make the problem obvious, change the logs so it will be obvious next time. Even with a bugfix and regression test, there will be similar bugs it will help catch. Or at the very least help you quickly prove that a new issue you're seeing is not a regression of that past bug.