How can PHP sessions be effectively utilized to maintain user data and state across multiple form submissions, as suggested by experienced forum members?

To maintain user data and state across multiple form submissions, PHP sessions can be effectively utilized. By storing user data in session variables, we can ensure that the information persists across different pages and form submissions.

```php
// Start the session
session_start();

// Store user data in session variables
$_SESSION['username'] = 'JohnDoe';
$_SESSION['email'] = 'johndoe@example.com';
```

This code snippet demonstrates how to start a session and store user data in session variables. This information can then be accessed and utilized throughout the user's session on the website.