Fill out a Freedom of Information request with your local FAA office for flight plans involving your plane's FAA ID. You can also file a Freedom of Information request with your airport if it is owned by the local or state government. Most state governments have FOI laws that are similar to the Federal FOI. You will need to present ID to request flight-plan data.
Track your plane with a GPS tracker if the FOI request is otherwise impractical. Turn the GPS tracker on before placing it in the cargo hold of the plane. The built-in battery will last for weeks of use, as a GPS unit is just a satellite radio that only picks up GPS radio stations.
Retrieve the GPS tracker and plug it into your computer. Modern trackers will give you plot data that you can take to a professional mapmaker or read with the GPS tracking software. The software will display a satellite map of the area flown, overlaid with the flight plan with time markings along the route.
