What are the best practices for organizing and structuring PHP templates to handle dynamic content insertion?

When organizing and structuring PHP templates to handle dynamic content insertion, it is best practice to separate the HTML markup from the PHP logic to improve readability and maintainability. One common approach is to use a template engine like Twig or Blade to keep the presentation layer clean and separate from the business logic. This helps in easily managing dynamic content insertion and making updates to the templates without affecting the underlying PHP code.

```php
<?php
// index.php

// Include the template engine library
require_once 'vendor/autoload.php';

// Initialize the template engine
$loader = new \Twig\Loader\FilesystemLoader('templates');
$twig = new \Twig\Environment($loader);

// Define variables to be passed to the template
$data = [
    'title' => 'Dynamic Content Insertion',
    'content' => 'This is a dynamic content example.'
];

// Render the template with dynamic content
echo $twig->render('index.html', $data);
?>
```

In the above code snippet, we are using the Twig template engine to separate the presentation logic from the PHP code. The template file `index.html` contains placeholders for dynamic content like `{{ title }}` and `{{ content }}`, which are replaced with actual data provided in the `$data` array. This approach makes it easier to manage and update the templates with dynamic content insertion.