What are some best practices for handling file inclusions in PHP to avoid errors?

When including files in PHP, it is important to use absolute paths or paths relative to the root directory to avoid errors caused by file inclusion from different locations. Additionally, it is recommended to use the `require_once` or `include_once` functions to prevent multiple inclusions of the same file, which can lead to conflicts.

// Example of including a file using absolute path
require_once(__DIR__ . '/includes/config.php');