Follow airlines on social media sites. You may feel silly adding an airline to your “liked” pages on Facebook or following them on Twitter, but the benefit of doing so is the special offers you’ll receive. Airlines want to reward regular customers and encourage them to continue flying with them, so they will often advertise special low rates and discounts via social media sites only. Follow as many airlines as you can for the best chances of getting a sweet deal.
You're not crazy for thinking that a flight price has changed after searching it a few times in your web browser. Based on the cookies in your browser, flight prices do increase when a particular route is repeatedly searched, as the site wants to scare you into booking the flight quickly before prices get even higher. Always search for flights in incognito or private browsing mode to see the lowest prices.