Summarize this article in one sentence.
Incognito mode keeps the websites you visit from placing cookies on your computer. If a website notices that you've searched for the same flight multiple times, it will often automatically raise the ticket prices. If you browse in Chrome or Safari, press Control + Shift + N to open incognito mode. If you use Firefox or Internet Explorer, press Control + Shift + P.  Putting your browser in Incognito mode is especially important if you search on different days of the week. Otherwise, old prices will sometimes display in lieu of new ones, and you may miss out on the best price. If you'd rather not use your browser's Incognito mode when looking for tickets, delete your cookies after each visit to a travel site. Aggregator sites are a great tool to use if you'd like to shop around and compare multiple airlines against one another. Type in your departure and arrival airports and days of travel, and scroll through the different flight combinations until you find the cheapest. Many aggregate sites also have a low-fare calendar so you can see which are the cheapest days to travel in a 30-day period.  If you don't mind putting in a little more work, visit the cheapest airline's website after you've compared it with others on an aggregator site. Some airlines will offer special deals and discounts if you buy tickets directly from the site. Popular flight aggregator sites include Priceline, Travelocity, and Expedia. Budget airlines can afford to mark down their tickets because they don't offer in-flight conveniences like Wi-Fi, complimentary snacks, and reclining seats. Flying on these airlines can sometimes cost less than half as much as a flight on a more luxurious provider.  If you're flying with the U.S., Hawaii, and the Caribbean, check out airlines like Frontier, JetBlue, Southwest, and Spirit. Or, if you're flying in Europe, try booking through Norwegian Air.

Summary:
Search for cheap airline tickets using your browser's incognito mode. Compare different airlines' ticket prices with aggregator websites. Fly on a budget airline if you don't mind flights without amenities.