Be it your very first international trip, or you have had dozens, a check-list always saves you from the fear of forgetting. Take a look-
1. Passports: Well the most obvious but the most IMPORTANT thing to check on. Your Passport and the required Visa-supporting documents preferably kept all in one place.
2. Passport-size photograph: If you are going to apply for Visa-On-Arrival, a pre-check on the specifications and a few spare copies would be wise.
3. Currency: It it best to have your currencies sorted before you land at your destination so as to save on time, get a better value of exchange. However, keeping a few of your origin country currency notes for a back-up in case of emergency is also a good idea.
4. Copy of the Bookings: Be it the details and vouchers of your hotel/home-stay, or the taxi which is going to pick you up from the airport, a printed copy or a screenshot might help in case you cannot connect to the WiFi to rely on your email.
5. SIM card and Roaming: You may choose to activate international roaming beforehand if you want to keep your number operational while on the trip. You may even want to rely on public WiFi, or you may want to buy a local SIM and use the talk-time as well as data. DECIDE in advance and plan accordingly. Keeping a spare phone is also a good idea if you want to have both your cards on.
6. Stationary: Keep a couple of pens handy for you and your companions (if any) as you may need to do a lot of paperwork. A small notebook is always a SAVIOR when you want to note something important and your phone doesn't have enough battery.
7. A warm layer: Airports and flight at times may feel like you are in a refrigerator! Cozy-up yourself with an extra warm layer!
8. A lot of enthusiasm and a smiling face :)