Use a tripod or stable surface
Clean the camera lens
Turn off flash
Turn off Night Mode if it causes blur
Use the rear camera
Tap and hold to lock focus and exposure
Lower exposure by sliding the sun icon down
Use a third-party manual camera app if available
Set ISO as low as possible
Use a longer shutter speed if the app allows it
Keep the phone very still during the shot
Use a timer or remote shutter
Shoot in a dark location away from city lights
Frame the sky with some foreground for scale
Take multiple shots
Edit brightness, contrast, and color afterward