Make sure your controller is properly connected to your computer via usb or bluetooth and powered on.
Begin pressing buttons on your controller and moving the joysticks.
Each button press and joystick movement should be reflected on the visual representation of the controller displayed on the screen.
Verify that each button and joystick on the visual controller lights up, changes color, or moves as expected when you interact with your physical controller.
Stick drift can also be tested by checking the X,Y coordinates or each stick.
Numbers slightly outside of the range of 0 are normal as controllers will not always center perfectly at 0,0.