Instructions and feedback help users complete the form and avoid errors. This can include hints, tips, examples, placeholders, error messages, success messages, or progress indicators. To provide effective instructions and feedback, use the <input> element's placeholder attribute to display a short example of the expected input format or value. Additionally, use the <input> element's required, min, max, minlength, maxlength, pattern, or type attributes to specify input constraints and validation rules. Also, use the <span> element with the aria-live attribute to display dynamic feedback. Remember to use clear and polite language for instructions and feedback. Avoid using vague, technical, or negative terms that may frustrate or discourage users.