Flexibility in travel dates is one important factor if you’re trying to find cheap flights. Airfares can vary widely in just a few days, and it can pay to use a travel site that checks several days either side of your preferred date. Many fares are lower during the week rather than Saturday and Sunday, and traveling off peak will also save you money. Flying to Europe is an obvious example; plane tickets are typically a lot lower in winter and fall, rather than summer. If you’re planning your trip a long time in advance, many airlines and travel booking sites offer a low fare alert system. Once you have input your destination and dates, you can get regular emails alerting you to any price changes to the fare. It’s an effective way to save on the airfare without checking it yourself every day.