There are several DIY methods to test air quality yourself. One common method is using an indoor air quality monitor, which measures various pollutants and provides a report on the air quality levels. Additionally, you can use test kits to check for specific pollutants, such as radon or mold, or conduct a visual inspection for signs of mold or moisture. It's important to note that DIY testing methods may not be as accurate as professional testing and it's recommended to hire a certified professional for comprehensive air quality testing.