Give Yourself Time
Although the Form itself suggests that it will take about an hour and 15 minutes to fill out, in reality, filling out and filing the online application will probably take you about 3 hours. Make sure to give yourself a head start by setting aside enough uninterrupted time to work on it.
To fill out the online application, you will need a computer, a valid passport, a digital photograph, the details of your intended trip, information about your previous travel to the U.S., and your biographic information. Gathering all of your information and documents together in one place, in advance, will make filling out the application much easier.
The Form DS-160 times out very quickly. If it times out, and you have not saved your information, you will lose all of the work you have already done. To avoid this very annoying result, make sure to save your work often. Once you start filling out the application, you should save the application to your hard drive at the end of each section before going on to the next section.
Review Your Work
Once you have entered all your information into the online Form, you will be given the opportunity to review the application. Take the time to carefully review your application to ensure that everything is entered correctly.
Print the Confirmation Page
Once you have submitted the online visa application page, you will receive a confirmation page. Be sure to print that page, because you will need to bring it with you to your visa interview.
If you have criminal convictions, have a medical ineligibility, have previously been denied entry into or removed from the United States, or are inadmissible to the United States for any other reason, you must disclose that information on your application. You may wish to consult with an immigration attorney before filing your application.