For someone moving around taking 2-8 flights per year, saving money on flights can be very good for one's budget. From what I know (which admittedly isn't the most on the topic), the most inexpensive way is to find extremely discounted flights on blogs or other forums for flights. Most of these flights will not be going to the destination you are looking for exactly but will generally be going to major international hubs such as London, São Paulo, and Hong Kong (One site I have found that lists such flights is secretflying.com).
After flying into this destination, the next step would be to book a more local airline for an inexpensive ticket. The best major search engine that I know for that is kayak.com. Right now that is the least expensive way I know to book a flight. I have read about getting credit cards for the purpose of getting tickets (but a good cash back card seems to be a better deal from what I know), skiplagged.com, and other promotions. The blogs and forums get much better deals than what I generally see (Round-trip $500-$600 to Europe vs $900 I can get myself). This could be a good thread if others who know of a better way to get cheaper flights add to this post.
After flying into this destination, the next step would be to book a more local airline for an inexpensive ticket. The best major search engine that I know for that is kayak.com. Right now that is the least expensive way I know to book a flight. I have read about getting credit cards for the purpose of getting tickets (but a good cash back card seems to be a better deal from what I know), skiplagged.com, and other promotions. The blogs and forums get much better deals than what I generally see (Round-trip $500-$600 to Europe vs $900 I can get myself). This could be a good thread if others who know of a better way to get cheaper flights add to this post.