How can I use error reporting to help diagnose a 500 error?

Enable error reporting in your PHP configuration. In php.ini, set `display_errors = On` and `error_reporting = E_ALL`. This will display detailed error messages directly in your browser, which can provide valuable clues. However, remember to disable these settings in a production environment for security reasons. For WordPress, enabling `WP_DEBUG` in `wp-config.php` serves a similar purpose.