Stopovers can range from a mere hour to even a full day (or more), so it's really up to you whether you would prefer paying less for your flights in exchange for doing some time at the connecting airport. The biggest issue is that time spent in airports eats into the "free" time you would otherwise enjoy at your final destination. If you do settle for a trip with a long layover, check into sights to see or activities to do near your layover airport. A 10-hour layover might provide the perfect opportunity to visit a famous landmark or explore a new city. To each, his own.
If you are going to fly when everyone is flying, then you’re ticket is going to cost more. Try to be flexible with your dates. If you are dead-set on visiting Paris, go to Paris in the spring or fall when fewer people visit and airfares are cheaper. But if you want to go in the middle of August? You’re out of luck. Hawaii over Christmas? Good luck!
In Google Chrome or Safari, incognito is enabled by hitting Command (or “Control” if using PC), Shift, “N”. For Mozilla Firefox or Internet Explorer, hit Command (or “Control” if using a PC), Shift, “P”. This will open a new browser window where your information is not tracked, thus not inflating prices as you search. Note: if you're using an older version of OS X, open Safari then click “Safari” in the menu bar, and select “Private Browsing”.