If you plan to visit a foreign country more than once this year, there’s a ticketing strategy worth noting. It’s called nesting. And it will save you money.

For example, instead of buying two more expensive round-trip tickets in advance between New York City and Paris, just buy one discounted round-trip ticket from the U.S. on Airline One that departs in May and returns in September or October. Then buy a second round-trip ticket on a different airline that starts in Paris in June and returns in late August.

Essentially, one ticket nests inside the other, and you’ll almost always save money. On advance purchase discounted tickets for domestic flights, you can do the same thing in the U.S.