Tips for upgrading an existing site to a Drupal distribution

A current project we're working on at Chocolate Lily involves upgrading a Drupal 6 site to use the Drupal 7 Open Outreach distribution. It's the first time we've used a Drupal distribution for an existing Drupal site instead of a new one. Having worked on my share of hairy Drupal upgrade projects, I went into this project with a fair bit of apprehension.

But I've been pleasantly surprised. The basic upgrade process was relatively quick and painless.

Tips for building a site off a Drupal distribution

As the first few organizations start to try out our Open Outreach distribution, I'm realizing there's a lot to figure out as you build a distribution-based site. Like how much should you customize the site versus taking it as it is? And how do updates and upgrades work? So here are a few pointers. If you have more, please leave comments below.