Sitting on #drupal-support on IRC, you see people drop by with update problems from time to time. With Drupal 6.21, 6.22, 7.1 and 7.2 released earlier in the week, today was such a day.
The person in question had attempted a Drupal core update via drush, but ran it in the wrong directory. Drupal had picked up this incorrect location for its core modules, so when the drupal-6.22 directory got deleted, it was unable to load any of the core modules. Oops.
This led me to wondering whether the way I manage my Drupal updates is odd and whether sharing it would be useful. Being an open source person, I am of the opinion that sharing is virtual always useful (except when it comes to cheese) so I'll document the way I manage updates here.