I love pragma marks. They just make reading your code so much easier, especially for other developers looking at your code for the first time. To use them, organize your methods in logical groupings and then add this line (including the dash) to your code.
Example:
#pragma mark - UIViewController
When you do this, XCode will organize your code with separators when you click on the navigator. When your code base gets huge, this will be exponentially more helpful. Give it a try!

For more, I liked this NSHipster article.