Applying for an O1 Visa can be a daunting process! It requires a lot of documentation and paperwork, but with careful preparation you can make the process much easier. First off, you'll need to provide proof of your extraordinary ability in the field in which you are being sponsored. This might include awards or recognition from peers, publications or other evidence of renown. Additionally, you'll also need to submit at least two letters from experts testifying to your achievements.
Furthermore, (you should) provide evidence that shows how your work has contributed substantially to the field - this could include articles written about yourself by respected media sources. As well as providing information on your qualifications, it's also important to demonstrate that you have a job offer in the U.S., and will be able to support yourself financially whilst working there. Lastly, don't forget any legal paperwork such as contracts and employment agreements!
All these documents are integral for successfully applying for an O1 Visa; although it may seem overwhelming at first, taking care when preparing each individual item will ensure everything runs smoothly and enable you to focus on achieving your goals!