Flush your brake fluid
Changing your brake fluid is very important. If your brake pedal has gotten squishy over time, there's a good chance you need to flush out -- not top off -- your brake fluid. A quick primer on why: Brake fluid is hygroscopic, which is the scientific way of saying it absorbs water from the atmosphere. That's a problem because water boils at a much lower temperature than brake fluid -- which leads to air in your brake lines, which means when you step on the pedal, you're literally pressing on air. The older your brake fluid is, the worse it gets. You can get away with every other year for this one, but if you want to do it every year, that's even better.
Many people are afraid to touch anything on their brakes, out of fear of, you know, not being able to stop. But flushing your brake fluid is one of the easiest things you can do. You can buy kits to help you do it yourself (pro tip: do that!), or you can enlist a helper to simply press on the pedal as you cycle the fluid through. For a step-by-step guide, go here.