Webform design recommendations

It's cool when web forms have been created wisely and it’s absolutely obvious how to work with them. Use these recommendations to create smart forms:

• Don't add unnecessary fields on it. Simple, but true. Each field on the form must be used. If you don't need it - delete it! This recommendation does not mean that all fields on the form must be required.
• Users must clearly understand what to fill out. Before filling in, it should be clear which fields are mandatory and which are optional.
• Users must clearly understand how to fill out. All formats and restrictions should be clear before filling out, and not after sending.
• Validatable fields are validated during the completion, not sending.
• All data that can be filled in automatically must be filled in automatically. E.g. Zipcode or delivery address based on history.
• Fields like a phone number or delivery address should not be sensitive to format and must be autoformatting by the system.
• If the form is too big to be filled out at once - user must have a possibility to save it to have the ability to continue later. With this saving type, some of the mandatory fields can be empty, so the system saves the form as a draft.
• Users must clearly understand how to save the form state, whether the button needs to be pressed or the form has autosave function.
• Sometimes it is useful to save the form to pdf format to have a possibility to discuss it with the boss or forward to someone.