Put the emphasis on domestic flights early on in the game. You’ll do the international ones once your airport evolves. Lower the prices for flights that are always full and increase them for those scarcely filled flights. It is always a good idea to upgrade just one plane at a time. The better it is, the more revenue you’ll get and can then move on to other planes. Connect the game to Facebook and let your friends help you out. You can get some fairly useful rewards. Use hangers to improve maintenance of your airport, control towers to increase connections. If you tap the green circles on the map, you’ll get some extra money from satisfied customers.