For enhanced organization and to avoid naming conflicts, I recommend using a PHP class for your customizations. Follow this basic structure in your master.php or custom.php file, and you’ll be on your way to a more professional customization environment.
class my_customizations {
public function __construct() {
add_action('template_redirect', array($this, 'front_end'));
/* Hooks and filters that need to fire early go here */
}
public function front_end() {
/* Hooks and filters that affect the front end _only_ go here */
}
}
new my_customizations;