Choose your seat later.
Some airlines charge you to pick your seat when you book online, adding even more to the bottom line of your ticket cost. If you show up early on your travel day, you can still get suitable seats. Some of the best seats get held back until flight day, unless others are willing to pay extra for them ahead of time, so you still have the chance at one of those.
Pack your own snacks.
Unless you're flying internationally, it's rare your flight comes with a free meal. Snacks on the plane are not cheap and almost never healthy. So don't rely on what's on the small menu and instead tuck some of your own snacks – granola bars, homemade muffins, nuts, quick snacks, fruit and trail mix all make fantastic travel foods – into your bag and eat a lot better, and cheaper, than other passengers.