Clean the camera lens
Wipe the phone camera lens with a soft microfiber cloth
Tap to focus before taking the photo
Hold the camera steady
Use both hands or a tripod
Increase the shutter speed
Improve lighting
Avoid zooming in too much
Check for motion blur from moving subjects
Turn on image stabilization if available
Disable digital zoom when possible
Use the correct focus mode
Update camera app or device software
Remove any protective case blocking the lens
Check for condensation or dirt on the lens
Retake the photo at higher resolution
Edit sharpness carefully in a photo editor