On a multiple leg international flight, consider different carries for domestic segments. For example, if you are purchasing a ticket from New York to Osaka, Japan, look into two different tickets: New York-Tokyo, then Tokyo-Osaka. Domestic flights in Japan are a standard price on Japanese carriers. Compare the price of a one-ticket trip to your destination with the cost of two or three tickets, keeping in mind taxes for each segment.
Some cities have special low-cost carrier terminals. Kuala Lumpur has two international airport, for example. One receives flights from discount carriers, and the other accepts bigger airlines, such as Air Malaysia, Air Canada and American airlines. Free transfers are available between the two terminals.
As an example, Air Asia's service is entirely customizable. Tickets don't include meals or checked luggage; these services must be purchased as an upgrade. Flying into cities with similar low-cost, customizable service will allow you to find low-price connecting flights. Search for low-cost carriers in the country you are traveling; consider what you need for your level of travel. Maybe you don't need two checked bags or in-flight entertainment, and you may be able to save money that way.
