It is recommended to use shutter as the main method. When the lighting conditions are not good, the shutter speed should be guaranteed first. If you find that the aperture value is flashing, it means that the exposure is insufficient, then don't lower the shutter speed. You can improve ISO by setting ISO to automatic first. However, when ISO is automatic, the maximum value is 1600. If the aperture value still flashes, manually adjust the ISO to 1800 or higher.
Another problem is to pay attention to white balance. If the effect of automatic white balance is not ideal, you can try other white balance methods.
Another method is to store in RAW format, which is convenient for later adjustment.