it is advisable to print out confirmation of airline tickets and accommodation. Quite often the host country's security staff will ask for guarantees of accommodation and refunds;
For international flights , familiarize yourself with customs regulations on importing goods. What is allowed in our country may not be allowed in another;
Pack 2-3 days before departure. Additionally, you can make a list of everything you need. This way you will not forget anything from your belongings and documents;
it is recommended to arrive at the airport 2-3 hours in advance. Then you will have enough time to understand the airport system and go through all the necessary steps before the flight.