File a flight plan with the United States Federal Aviation Administration. If you are making an international flight, you will use FAA form 7233-4. You can download this form from the FAA's website. You should note your expected time of return and add the words "advise customs" on your flight plan. This helps to inform the FAA that you will tell the customs officials in the destination country of your expected return time. If your plans change, you will be required to notify the FAA of your new return time at least one hour before you return.
Land at an international airport of entry in your destination country.
Fill out the required customs and immigration forms presented to you by customs and immigration officials at the airport of entry. These forms will vary among countries where you will be traveling. You are required to carry a passport for all destinations outside the U.S. For U.S. territories, you are only required to have a valid photo ID.