What are some common mistakes when handling $_POST data in PHP?

Common mistakes when handling $_POST data include:

• Not checking request method: Ensure the form is submitted via post method. Check this with $_SERVER["REQUEST_METHOD"] === "POST".
• Forgetting to sanitize inputs: Always sanitize user inputs to prevent security issues. Functions like filter_var and htmlspecialchars are useful.
• Not handling empty fields: Check for empty or missing fields using isset() or empty() functions to avoid errors.
• Incorrect form encoding: For file uploads, ensure enctype="multipart/form-data" is set in the form tag.