I've recently started experimenting with using drush core-quick-drupal to create drupal sites strictly for creating patches to share on drupal.org. I'll walk you through my several pitfalls on the road to making this command work on Ubuntu 12.04. Hopefully, with this advice in hand, you'll be able to spin up fresh drupal instances in no time!
I'll walk you through how to setup your environment and Drupal settings.php file to keep your credentials out of your code. This makes your settings.php file easier to work with in Git across multiple environments by allowing you to have different credentials for work laptop than the server. You can also keep your settings.php file under source control and even try daring schemes like chmod 644 settings.php! Read on to learn more of this trickery.