If you're like me, a lot of your projects aren't very well documented. If you look over Github or Drupal.org a significant number of projects are poorly documented. I'm only aware of a few people who regularly document their projects well. In an effort to improve the documentation on the projects I maintain (or try to maintain) I've started to schedule an hour per week to just write better documentation.
An important element to note is that this is scheduled time. I've added it to my calendar and scheduled it into my week. To keep this as a useful part of my time I've scheduled it for the second hour of my work week. This gives me time to get through my email and any communication I need to get done (or any slow starts). Then, I start writing documentation before the week gets in the way.
If you'd like to start writing better documentation I invite you to join me in spending an hour a week improving the documentation in our projects.