I know that your flights can be cheaper when you switch your browser to private browsing (like Incognito mode for Chrome, etc)
There's also apps that I use to track certain flights from certain cities, etc such as Hopper. And I use Google Flights to also help me book a flight.
Something one of my friends did and she got free trips to Chicago, Dayton, and Hawaii was that she opened a credit line with an airline and use that credit card to pay off other people's debts (bills, etc) and they gave her the cash when she was ready to it pay off. (It was people like father, etc so it wasn't just some random friend who might not have had the funds). The goal was to spend some certain thousand dollars in the remainder of the year or something and the rewarded her with hella miles.